Mary Maxwell, 24, was adopted by her cousin after her aunt and both of her parents died young - from heart attacks related to obesity.
At just two-years-old, Maxwell weighed 50lbs which snowballed to 220lbs when, aged 12, her adoptive father also passed away from cancer.
Severely depressed, Maxwell's food addiction grew out of control until she reached 300lbs.
But when she met the love of her life, things changed and for the first time in years she began to consider her future.
Maxwell knew she needed to lose weight for the sake of her health.
Maxwell, who is an English teacher from Portland, USA, said: "I'd been overweight and heavily bullied my whole life.
"My parents and whole family were morbidly obese.
"I was severely depressed and suicidal. Not many people knew how bad the bullying really was. I thought that it would get easier as an adult but it never did.
"Adults would gossip about me, 'forget' to invite me to work gatherings and I even noticed it in clothing stores.
"I would walk in and magically all of the sales associates would disappear. I would ask them questions and be given a dirty look and then ignored."
She added: "Being a young girl who has dealt with the pain of losing three parents, been shunned by society, and bullied was a very hard reality to get used to.
"Food was my best friend, my comfort. I didn't need it to understand me, unlike my peers."
The turning point came when Maxwell was asked on a date by her good friend Josh Parker.
The happy pair fell in love and began to discuss their future together.
Maxwell said: "I had become involved in a serious relationship and my future became more real to me.
"I knew I wanted to be alive to have a family and be able to be healthy.
"I didn't want to end up like my family who died so young from their battle with obesity.
"I decided enough was enough and it was time to make a change. In the past I had never really cared about a future because I was so depressed.
"With Josh in my life I knew things needed to change. I saw a doctor who talked with me about weight loss surgery."
At 20 years old, Maxwell had gastric bypass surgery and the weight quickly began to shift.
The surgery gave her a new lease of life - she took up sports and travelling, and spent two years exploring Asia. She also built up a loyal following of 56,000 fans on Instagram.
However the dramatic weight loss left Maxwell with a lot of excess skin.
Maxwell said: "I thought that losing the weight, people would stop looking at me with disgust and shame. Yet now when I go out in public I am still dealing with those issues.
"People will ask why my arms, legs and stomach look so gross or weird and even friends will make fun of it.
"I cannot go out in public without a shawl to cover myself or my spandex to hold in the skin. I cannot go to the beach or wear clothing that I should rightfully be able to wear after shedding the weight.
"I emotionally cannot be myself in public or with my boyfriend."
She added: "I have even asked him to hold off on proposing to me because I am dreading trying wedding dresses on because of my disgusting skin.
"A happy time for a woman has turned into a nightmare because of my skin."
Maxwell is currently working towards paying for reconstructive surgery so she and Josh can finally say 'I do'.
The 24-year-old is now trying to raise money for surgery through a GoFundMe page.
Writing on her fundraising page she said: "Here I am, in tears over the fact that complete strangers want to help me on my journey.
"I have never been one for handouts or to ask for 'charity' but if people really want to help me complete the last step of this journey I will accept it."
She added: "If I am never able to afford this surgery I know I will still be ok, I am a fighter and a survivor.
"As long as I am at a healthy weight and happy that is all that matters."