Sounds like you have the right attitude, and you've got plenty of time. If I were you I would get myself a weekend job at a flight school and see if they'll pay you in flight time. If not, then ANY weekend job and spend it hour building (plenty of ways to hour build cheaply starting from £60 with a share) By the time you're old enough to get a CPL you'll have the hours.. Along the way, you can pick up your ATPL exams, IRR, then IR (CBIR route, obviously). That'll leave you a 15 hour CPL to get and the multi time for your MEIR. Get your parents on board by promising to move out when you get a job!
If you stay focused you'll be debt free and flying a Jet while your friends are graduating with Mickey Mouse degrees and loads of debt.