Go for the degree first, then the aviation career.
If aviation doesnt like you, or you dont like it, you'll then have something to fall back on.
The only caveats I would add are;
1 - Make sure that the degree is mainstream enough to further your career outside your initial asperations, i.e. 4 years studying poetry and welding techniques won't get you all that far in the real world.
2 - Start saving now, or find a rich benefactor, either career option is going to cost you a fortune.
Good Luck.