A passing thought.
If you are likely to have that sort of money available, then you could do the majority of your training between school and university, and during the long university vacations. You should then, all going well, in 4-years have an ATPL and a degree, and far more options than most!
You'll also be knackered, but you'll get over that.
In the meantime, as you say, get some quality flying in so that you are sure it's what you really want.
G