future atc..... I had the same plan in the 1970s. I stayed on to get 'A' Levels with the objective of joining NATS straight from school. Sadly, the 1970s oil crisis resulted in a suspension of recruiting, so I ended up as an ATC assistant for 2 years. I left to do a science degree, and when NATS started cadetships again, (1978), I joined straight from university.
It's always nice to have something to fall back on, and the ATCO training course was much harder than being at university, but was more rewarding and well worth the wait.
Whatever you do, good luck and have fun......As one of our ATC supervisors pointed out:-
"Life is not a dress rehearsal"!