What do I do about people making fun of my disability?

I'm sorry this is going on in your life. Some kids are socially stupid... they have no idea others have feelings because their world is all about them. Teens/kids are just learning how to socialize and many times, they really show their lack of experience and ignorance.

Maybe you could talk to your parents and ask them if they'd talk to the principal or school guidance counselor about this. These girls making fun of you need to realize what they are doing is very hurtful to you. And someone needs to let them know.

Immature people make themselves feel better by putting other people down. Chances are they make fun of a lot of people for different reasons- what they wear, what they look like, how they act, etc. If it gets to the point of bullying, you need to report it to the school. But most kids in school get made fun of for something. Things get much better as you get older and you're around more mature people.
BTW, I don't know what your disability is, but usually if you laugh at yourself first, it's much harder for other people to laugh at you. There's a comedian, for example, with multiple sclerosis, who makes fun of her own awkwardness and slurred speech.

Start by telling your school. If they don’t do something TO THE BULLIES, call the police and report them. The police probably can’t do anything, but if you call while you’re still at school, the school will then do something in order to save it’s image.

ignore them.......