Considering the fact that you started exercising more you should've answered me with a YEEEAH BUUUDDY.
I don't know what these forms you speak of are but how many do you have till you reach your final form?
Sixth form is after secondary school and before university. It's the two years you have for doing A-levels, the exams needed for getting into university. You start sixth form from 16 and finish at 18. University starts at 18. '-' X
College is university level. I'm 21 and have been going to college since I was 19. I would have started at 18 but I took a gap year.