Teen Sick Of Parents Who Always Prioritize His Disabled Brother, Refuses To Be His Free Babysitter

I’m 17M and have a 15M brother with severe disabilities—he can’t walk, talk, or eat on his own, so most of my parents’ time and energy goes to him. When I was younger, my grandpa raised me from age 2 to 7 and stayed heavily involved because my parents couldn’t be. He helped with school stuff, took care of me when I was sick, and paid for things like lunch and field trips—things my parents wouldn’t or couldn’t handle.
As I got older, I became more of a caretaker at home—cooking, running errands, and helping with my brother’s needs. Meanwhile, my parents never supported me academically or thought about college for me. When my guidance counselor reached out multiple times about college forms and financial aid, they ignored her.
Recently, they asked me to babysit so they could go out. I said no. They told me I should help my family more, considering “all they’ve done for me.” I asked them to name one thing they’ve done for me, not my brother. They couldn’t. They called me spiteful and immature. But honestly, I’m just tired of being the forgotten kid.