Sharing a throwback post of herself from years ago, Jesy wrote a heartbreaking caption that read, '6 months ago this girl was someone I just wanted to forget. I wanted to erase her from my mind and everyone elseās memory.
'I didnāt see her as Jesy I saw her as āthe fat one from Little Mixā. Up until now I hated her, not because sheād ever done anything bad but because I was made to hate her by endless amounts of trolling.'
Swipe through to see Little Mix's transformation through the years...
2011
After being put into a group by Kelly Rowland on The X Factor in 2011, the Little Mix girls rocked denim and trainers as they posed at the Judges Houses' stage of the competition.
Jesy Nelson reveals heartbreaking self-doubt in inspirational throwback post
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2018
The girls then changed into smart black and white suits for their first ever performance of 'Woman Like Me' with Nicki Minaj.
2011
After being put into a group by Kelly Rowland on The X Factor in 2011, the Little Mix girls rocked denim and trainers as they posed at the Judges Houses' stage of the competition.
2011
Throughout their time on The X Factor, Jade, Perrie, Jesy and Leigh-Anne stuck with the same 'colour and prints' theme for performances, each making an identify for themselves.
2011
Attending the Twilight Breaking Dawn Part 1 premiere in 2011 with their X Factor mentor Tulisa, the Little Mix girls dressed up in stunning LBDs.
2011
After winning The X Factor ahead of Marcus Collins, Little Mix started to make an identity as a band, co-coordinating their outfits both on stage and at events.
2012
One year on from their historic win on The X Factor, Little Mix returned to perform their brand new single, looking more grown up.
2012
At the launch for Little Mix's debut album 'DNA', Jade, Perrie, Leigh-Anne and Jesy looked stunning in black outfits.
2013
All of the Little Mix girls have experimented with their hair colours, but in 2013 Perrie went for purple, whilst Jade was rocking the colour blue.
2013
Attending their first ever BRIT Awards in 2013, Little Mix dressed up for the occasion, all wearing totally different outfits.
2013
Experimenting even further with her hair in 2013, Perrie changed her look from purple to dip dye pink later in the year.
2016
After taking some time off to work on their new album, Little Mix returned in 2016 with a brand new look. Looking a lot more grown up, the girls started to wear a lot more custom-designed outfits on stage.
2015
Perrie couldn't resist getting into the Disney spirit in 2015 when she made a trip to Disneyland Paris!
2016
Walking the red carpet ahead of their first ever BRIT Awards performance, Little Mix oozed glamour as they invited their mums along for the party.
2016
That same night the girls took to the stage in matching green and black outfits to give an incredible performance of their hit song 'Black Magic'.
After taking more of an interest in fashion, attending various fashion events with her band mate Jade Thirlwal, Leigh-Anne started to take inspiration, wearing this cute number for her birthday in 2017.
2017
Little Mix embraced the race driving theme brilliantly in 2017 when they performed at F1 Live in London.
2017
The girls attended the Nickelodeon Kids' Choice Awards in Los Angeles in 2017, rocking the red carpet with their different outfit choices.
2017
Whilst Perrie, Jade and Leigh-Anne stuck with their natural hair colours in 2017, Jesy experimented a lot, even dying her hair bright pink!
2018
Looking completely stunning, Jade, Leigh-Anne, Jesy and Perrie rocked the red carpet at the 2018 BRIT Awards. Whilst most fans loved their look, Jesy, Jade and Perrie were quick to mock Leigh-Anne for wearing her 'dressing gown'.
2018
Little Mix stars Leigh-Anne and Jade attended The British Fashion Awards in 2018, wearing stunning dresses to the prestigious event.
2018
The girls went for a more retro look during a performance to their fans in Germany in 2018.
2018
At the launch of their amazing album 'LM5' in 2018, Leigh-Anne, Jesy, Perrie and Jade looked casual and chic as they signed copies of their album for fans.
2018
Ahead of their performance with American rapper Nicki Minaj, Jesy injected a bit of colour into Little Mix's red carpet look at the 2018 MTV EMA Awards, whilst Leigh-Anne rocked green dreadlocks.
2018
The girls then changed into smart black and white suits for their first ever performance of 'Woman Like Me' with Nicki Minaj.
2011
After being put into a group by Kelly Rowland on The X Factor in 2011, the Little Mix girls rocked denim and trainers as they posed at the Judges Houses' stage of the competition.
2011
Throughout their time on The X Factor, Jade, Perrie, Jesy and Leigh-Anne stuck with the same 'colour and prints' theme for performances, each making an identify for themselves.
2011
Attending the Twilight Breaking Dawn Part 1 premiere in 2011 with their X Factor mentor Tulisa, the Little Mix girls dressed up in stunning LBDs.
2011
After winning The X Factor ahead of Marcus Collins, Little Mix started to make an identity as a band, co-coordinating their outfits both on stage and at events.
2012
One year on from their historic win on The X Factor, Little Mix returned to perform their brand new single, looking more grown up.
2012
At the launch for Little Mix's debut album 'DNA', Jade, Perrie, Leigh-Anne and Jesy looked stunning in black outfits.
2013
All of the Little Mix girls have experimented with their hair colours, but in 2013 Perrie went for purple, whilst Jade was rocking the colour blue.
2013
Attending their first ever BRIT Awards in 2013, Little Mix dressed up for the occasion, all wearing totally different outfits.
2013
Experimenting even further with her hair in 2013, Perrie changed her look from purple to dip dye pink later in the year.
2016
After taking some time off to work on their new album, Little Mix returned in 2016 with a brand new look. Looking a lot more grown up, the girls started to wear a lot more custom-designed outfits on stage.
2015
Perrie couldn't resist getting into the Disney spirit in 2015 when she made a trip to Disneyland Paris!
2016
Walking the red carpet ahead of their first ever BRIT Awards performance, Little Mix oozed glamour as they invited their mums along for the party.
2016
That same night the girls took to the stage in matching green and black outfits to give an incredible performance of their hit song 'Black Magic'.
After taking more of an interest in fashion, attending various fashion events with her band mate Jade Thirlwal, Leigh-Anne started to take inspiration, wearing this cute number for her birthday in 2017.
2017
Little Mix embraced the race driving theme brilliantly in 2017 when they performed at F1 Live in London.
2017
The girls attended the Nickelodeon Kids' Choice Awards in Los Angeles in 2017, rocking the red carpet with their different outfit choices.
2017
Whilst Perrie, Jade and Leigh-Anne stuck with their natural hair colours in 2017, Jesy experimented a lot, even dying her hair bright pink!
2018
Looking completely stunning, Jade, Leigh-Anne, Jesy and Perrie rocked the red carpet at the 2018 BRIT Awards. Whilst most fans loved their look, Jesy, Jade and Perrie were quick to mock Leigh-Anne for wearing her 'dressing gown'.
2018
Little Mix stars Leigh-Anne and Jade attended The British Fashion Awards in 2018, wearing stunning dresses to the prestigious event.
2018
The girls went for a more retro look during a performance to their fans in Germany in 2018.
2018
At the launch of their amazing album 'LM5' in 2018, Leigh-Anne, Jesy, Perrie and Jade looked casual and chic as they signed copies of their album for fans.
2018
Ahead of their performance with American rapper Nicki Minaj, Jesy injected a bit of colour into Little Mix's red carpet look at the 2018 MTV EMA Awards, whilst Leigh-Anne rocked green dreadlocks.
2018
The girls then changed into smart black and white suits for their first ever performance of 'Woman Like Me' with Nicki Minaj.
She continued, 'Since filming my documentary for @bbcone and @bbcthree Iāve learned so much more than I ever expected to. Thanks to all the inspirational people Iāve met on this emotional journey, I now love the girl in this photo.
'Iāve made this documentary for 2011 Jesy and for anyone who might be feeling like she did. I refused to speak about how I was feeling for so long. I was embarrassed and scared to. But I was so wrong to feel that way. Please if you are feeling how I did, SPEAK ABOUT IT. Talk to your family, speak to your friends, thereās always help out there.
'If youād have told that girl one day you wonāt feel sad anymore, Iād never have believed you....and here I am. Now when I look in the mirror, I donāt see Jesy the fat one, I see Jesy the happy one.'
The inspirational post was flooded with likes and comments, racking up nearly 300,000 likes in just over an hour. Fans shared their love for the singer, praising her honesty, with one writing, 'jessyyyy this documentary is going to help so many people ā¤ļøā¤ļø', as another added, 'Iām so proud of you babe!! You are so strong and you inspire all of us š one of the strongest women I know! ! I love you loads ā¤ļøā¤ļø' sic
Jesy first announced the mental health documentary back in March this year, taking to Instagram to share a video of herself discussing the project and writing, 'Mental health awareness is something we should all be talking about more. Having suffered myself I decided I want to do something about it.
'So Iām pleased to announce I'm making a film with the BBC, telling my own personal story and exploring how social media, body shaming and trolling is effecting the mental health of young people.'
Congratulations, Jesy. ā¤ļø
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