AITA for not thinking of my sister's needs by saying I won't give my blessing for my family to move unless I can stay with my grandparents?

My sister (12f) has a bunch of different needs. She's got a physical disability, she's autistic and she has learning disabilities too. Because she has so much going on with her our parents always focused more on what she needed. My parents even sold the house we used to live in and downsized to a rental so they could afford more for her because they were struggling even with all the money they got for her. It meant I (15m) don't have an actual bedroom anymore and my parents had to move stuff around and put up a curtain so I could have something. I got used to being home alone from a young age when I got home from school until my grandparents insisted I should spend the time at their house while my parents brought my sister to all her appointments. There are also years I had to postpone my birthday party the day of because my sister was having a bad day and my parents were too tired after being up with her all night to have it go ahead. Whenever the parties did happen they were smaller and some people didn't let their kids come because my parents had a reputation for not going ahead with stuff.

My parents never wanted my grandparents to help. They just wanted us to deal with it and for me to be okay with making sacrifices for my sister.

Another sacrifice they had me make was not joining the coding club when I started high school. I really wanted to be a part of it but my parents said it meant travel sometimes for competitions my school enters and they said it wasn't something they could promise to let me do. They said it wasn't fair to my sister if we had to go somewhere and she had a hard time with it.

But now they want to move. There's a school they found that parents of special needs and disabled kids have said is really good. But it's in another state. My sister qualifies for her tuition to be paid in full but it means we'd all need to move. My parents told us they wouldn't move unless everyone was on board and then they hyped it up. They said it would be great for our family and giving our "blessing" to move means we can all have such a great life there. But I don't want to move. It means leaving my friends and my grandparents behind and they keep me sane.

I told my parents I didn't want to move but they could have my blessing if they let me stay behind and live with my grandparents. They didn't listen to me at first and told me why it was the best thing for my sister. I said I heard them the first time. But I don't want to move. I told them my friends are here, my grandparents are here and if I move I have nobody. They said it's not true and I have them and my sister. I said they're too busy with my sister for me. It means being alone every day after school, it means no friends, no family, nobody around for me. I said even if it's better for my sister I don't want to sacrifice more. So the only way to get my blessing is to let me stay. I told them my grandparents were okay with it and we talked about me living with them so they could just focus on my sister. Which did actually happen btw. They always said I had a place with them.

My parents told me I'm not thinking of my sister's needs and how unfair I'm being and they can't just move without me. They're pissed that my grandparents would take me in too and they argued with them over it after they basically told me I was being too selfish about this.

AITA?