She subsequently had to have a hysterectomy and then went through an early menopause that triggered mental health issues and self-harming.
Fergison said she was dousing herself in scalding water daily as she tried to "wash" away the cancer cells.
“I was damaging myself so badly,” she said. “As soon as I got the all-clear I stopped doing it. If you’re told you are ill, it’s not just about the physical issue - somehow, you need to figure out what’s going on in your head with it all.”
The actress said that by this February, she was penniless.
"I didn’t have any money to do a weekly shop. I was trying to pay too many debts," she said.
"It was a really difficult time," she added. “Lots of people can relate to it. You’re trying to find a penny. You’re literally looking down your settee to see if you can find a quid.”
Fergison said it was a long way from her time on EastEnders, when she "didn't even look at the price of things".
She said that she sought help at Citizens Advice, and a staff member from the charity subsequently took her to a food bank.
“I sat there and cried and cried. It was shameful. How could I have been on EastEnders? How could I have been earning that much money and now I am here?," she asked.