Lisa Durrant, 33, was unable to get pregnant because she was so overweight.
Her weight crept up to 21 stone and for years she tried dieting, but without success.
So she eventually had an operation called sleeve gastrectomy which helped her halve her body weight and she is trying for a baby.
Lisa, from Burwell in Cambridgeshire, told the Mail: "I feel so much better now and I can't wait to have children."
Lisa piled on the pounds when she was bullied as a teenager.
This led to a vicious cycle of comfort eating multipack crisps and Haribo sweets to make herself feel better.
As she grew older, she became increasingly concerned about how her failing health was affecting her ability to have children.
She stopped having regular periods at the age of 17 and doctors suspected her obesity was affecting her fertility.
Lisa said: "I'd really wanted kids since I was 19 and if I hadn't been able to have them I would have been devastated."
Lisa tried several diets and even had a gastric band fitted in 2007, but it was removed three years later because it was damaging her stomach wall.
So in August 2011 Lisa opted for a sleeve gastrectomy.
This involved having two thirds of her stomach removed through keyhole surgery at a hospital in Australia, where she was then living.
The operation, which was covered by her private health insurance, cost £4,000.
Lisa said: "'It was a big decision, but I was so unhappy being overweight that I knew it was what I needed to do.
"I couldn't sit in cinema seat and plane seats were always a problem. It was so embarrassing and I felt so self-conscious.
"I didn't worry about the operation, I was more worried that my obesity would kill me. If I went on a short walk I would be out of breath. If I went up a few steps then I would start to feel extremely unwell."
Thanks to the operation, Lisa has lost more than 12 stone, and her dress size has shrunk from a size 28 to a size 10.
Before her weight loss, she typically ate McDonald's muffins for breakfast then large meaty sandwiches and cakes for lunch.
For dinner she would often eat whole Pizza Hut pizzas to herself and would snack on crisps, sweets and chocolate.
Today, she typically eats a small bowl of cereal or fruit for her breakfast. For lunch she will still have a ham salad wrap or pasta but it will be spread out throughout the day as she can no longer eat it in one sitting.
She said: "At first it felt a bit strange as I was used to being able to eat a whole pizza. Now I eat two slices and feel stuffed."
With her new-found confidence, Lisa decided to leave an unhappy life in Australia and move back to the UK to be with her family.
She has found a new partner, her periods started again and the couple are planning to have children together.
Lisa said: "I feel absolutely fantastic, I have a lot more confidence than I ever had before."