Hey, I'm new too, but yeah, welcome anyway! School used to be really bad for me too, when I first moved to secondary school (the first three years are the same as middle school I think) I only stayed for a couple of months because people were bulling me and because this was before i'd been diagnosed none of the teachers wanted to listen. so in the end I was home educated for nearlly two years.
I've been back at school for nearly three years now, and I'm part way through my GCSE's. I think that my ability to remember details really easily and to focus on things I care about have helped me a lot with that. My grades are usually pretty good too. your not the only one who worrys about the future, I go into the sixth form next year and every time I think about it I start panicking. Try not to let it get you down though, just remember that even if it seems scary and impossible now it will work out eventually. (Wish I always remembered that.)