I dont think it will be any drones for a while.
Even in military they use them only as "fly over" for spying or dropping bombs.
They use quite a while to program it on the ground, before the flight. And then someone still monitoring it and steering it. Main reason for usage of drones, is to save lives, in case they got shoot down.
Its a looong looong time before they trust 300-400 lives into computer with no one to operate it.
Reality now is that pilots is more of "system operators". How much of real navigation (using flight computer, conversion angle formulas and grid navigation) does pilots do now day? Nothing? And what about calculating length of the runway?
What we have now is kind of "drones", with pilots to operate them. 1 to operate and 1 as a back up. And as I said, I cant see it being different anytime in the near future.
Oil and stuff is different thing. Although they find new ways to get oil all the time. And Im pretty sure they will find another good sources for energy.
Anything we do in our lives is some form of risk. Any decision we take. In my opinion it well worth the risk, using your savings to become a pilot. But its all up to you.
No one here will be able to tell you for sure, how aviation gonna be in 5 years, 20 years or 40 years from now.