Guy I stopped talking to 5 months ago just followed me on Twitter?

Did you tell him the reason why you stopped talking to him? Have you stopped all forms of contact or could you still talk to him online without the parents knowing?

Him following you on Twitter doesn't mean much, if you really want to know how he feels then explain the situation with your parents to him if you are able to. See how he reacts; if he still has feelings for you he'll probably let you know. I don't think that it's a good idea to leave him for 11 months without any contact at all, especially if he doesn't know why. It might make him think that you're no longer interested.

He knows the reason...but I know that at the moment I can't make it work because of my parents.
A day after he followed me...he favourited a tweet that was somewhat old...I really wanna talk to him but I know at the moment it can't lead to anything

Well, if he favourited an old tweet then he is clearly looking through your feed so at least he hasn't forgotten you . Still, don't read into this too much because you can only know how he feels once you've spoken to him.

You said that it can't lead to anything, yet you'll be seeing him in September? Do you think that it's worth staying in touch somewhat until you can see him again, in case things can progress from there?

I really want to talk to him right now, but I know if I do a) my parents might find out and b) he'll distract me from my studies. So I think it's best if I don't contact him right now...

This is really petty but do you think I should favourite a tweet of his?
Thank you for your advice by the way