If I were you, I'd apply for sponsorship now. If you don't get it because you fail the aptitude tests or medical, you'll know where you stand. If you don't get it because they decide not to select you for suitability reasons (I know 18 doesn't seem young when you are there, but life offers an awful lot of experiences during the next few years), go to Uni, concentrate on qualifying yourself for an alternative career, but keep your interest up in aviation; my impression is that selectors value motivation and look for evidence that your stated desire has been reflected in your behaviour. When you graduate, apply for sponsorship again. If they still don't want you, consider paying for your own training, but do not expect to follow the fast-track route to a jet airline and be prepared for some employment disappointments and poorly paid jobs along the way (while trying to pay-off your training costs).
As for paying for your flying training while doing a degree, I'd ask 2 questions: why pay for your own training when you might be able to get sponsored; and is the degree the best choice a) for an airline pilot and b) for an alternative career if the airline pilot bit does not work out?
The best investment you could make now is the £165 for the easyJet/JMC sponsorship selection. It might change your whole life.
Whatever, good luck PWP
