If i dont get A levels i am stuffed as far as becoming a pilot is concerned
Your learning.
... and when you get to that point and start working you'll struggle to find a job that'll pay more than £16k per year (£12,700 take home).
Take into account your living expenses, travelling to work, getting a car, running the car, fixing the car, food, possibly lodge to your parents, I really don't think you'll be left with very much to put toward that £30k+ (to put it lightly) modular flying bill.
At this point I estimate you'd be 22/23 years old with a fATPL and back up job that could earn you £20k per year.
If you go to Uni you'll have some great life experience and meet some great friends, you'll be 21 when you graduate and 'should' land a £20k pa job straight away.
Applying for you first FO job you'll be 25 years old, trained pilot, University graduate, life experience, maturity, well travelled various job experiences.
Choice is yours (plenty of threads on 'Do I need a degree to be a pilot' and 'what degree is best to become a pilot')