Hi
I believe that in the current climate the best way to get a flying career today at your age is to join the RAF. If you can aspire to the lifestyle, I absolutely mean that. They will pay you to fly, you'll see the world, and if you've got the right stuff you will come out of there and become an airline pilot perhaps within ten years.
But you do have lots of other options being 17. Apply to CTC-McAlpine and look out for other sponsorships in the next year. If you want them you will find them!
You don't need a degree, but if you can't fly it's a useful back up.
Most importantly, stay out of debt.
Good luck!