You need to get away from this guy. No legitimate person would ask for money by untraceable means (gift cards, Western Union, etc...). You have been scammed and your chances to get your money back are pretty close to zero. Stop throwing away more money.
As AJ points out, go to your bank now and tell them that you have done this foolish thing and you need them to not only move your money elsewhere but you need to have them shutdown your account hard (lest you suddenly get hit with a lot of overdraft liability).
You're not going to jail, but you're in deep financial peril.

