It is time to talk to the guidance counsellor at your school. If you don't have one, talk to a teacher. They can speak on your behalf to your parents. They can confirm your claims that no one else is dressing this way. They can advise your parents that this in fact is a real problem for you making your life difficult.

I had a very strict mother when it came to clothing and other choices that made things socially difficult for me in highschool. My math instructor realised this and intervened with my mother on my behalf. Things were rough I admit with my mom after this but the problem stopped.