Stupidly enough I chose to do A level Physics also. I've only just started my AS levels and I do ft difficult. But I think it is gr8 fun because I have teachers who don't like teaching boring things, so there's always new angles and puns intended.
I think it is worth having a go at. Some things I didn't understand I'd just read up on and it was real simple after that. Think about getting a tutor (that's what I'm gonna do soon, if not now, nxt year). Anyway, gotta go do some h/w (Vectors and Scalars...yeh!!)