I'm sorry that you were and are so neglected and berated just for being sick, anon. It's already bad enough to just have to suffer from health problems, but then to be berated and neglected on top of it is so awful. I know what it's like to have to cope with the consequences of parent-imposed medical neglect and it is so horrible and alienating. How old is he exactly? He sounds like he's definitely on track to being a failson. Very weird that your mom is still hand feeding him while he's in elementary school because he doesn't want to have to stop looking at the television.
Unfortunately it's not uncommon for parents to invest their time, money, and emotional energy into their sons while neglecting their daughters. You deserve much better. I hope they come to regret having invested entirely into one child solely because he has a dick.