As far as I know, there aren't many cadetships where you don't have to pay for the training, and that means a SECURED loan (which would mean your parents signing for the debt), which I get from your post won't be happening.
The only cadetships I have heard of where you don't pay are in countries that you must be a citizen of (and in some a member of a certain minority or previously disadvantaged minority), such as Holland, Kenya, South Africa, Namibia.
Since the odds of actually getting a career in flying are slim at best, I would suggest you get a nice job doing what you're trained in and fly on the weekends. Flying will always be more fun when you don't "have to" fly.