OP, I think you need to really, REALLY consider almost any other living situation for the next few months. As someone else said, a bedsit only needs room for your bed and the baby’s cot. I say this not even jokingly, but as someone who has worked in both cancer care and hospice: living with your parents, as cruel as they sound, is not healthy, and it is especially unhealthy for a new mother and cancer survivor.
Some of the most important factors in life’s transitions (becoming a mother, navigating the time after having had cancer) are support and attitude. No, a positive attitude and all the support in the world sadly cannot guarantee someone’s survival from something like cancer, which can be heartbreaking, but on the other hand, having people be extremely unsupportive and even vile, like your parents, tearing you down so that you are unable to stay positive about ANYTHING, can cause a huge amount of stress, which isn’t healthy for anyone. It doesn’t mean your cancer would return, it won’t make you a bad mother, but it can very easily exacerbate your depression, and cause things like headaches, fatigue, and general pain - when we’re in a horrifically high-stress living situation, our bodies just can’t handle it. And it is true that the last thing any cancer survivor needs is added stress.
Your parents are wrong. They’re wrong about everything. They’re wrong about your screensaver, and they were wrong not to support you when you actually had cancer, and they’re wrong to compare you to your own baby saying that he’s much better than you were. To be honest, it sounds like one of those horrible situations where a mother doesn’t want anything good for a daughter or is jealous of her so tries to constantly tear her down and never supports her.
Please consider leaving as soon as possible.