Personal Account Frauded

I am a 20 year old student who made a very discouraging and costly mistake online, specifically on craigslist. I accepted a personal assistant job and ended up being frauded 4000 dollars out of my own personal checking account. This was money I did not have to begin with, but I was given a fake check (unknowingly obviously). Despite my efforts with the police department and the Bank, I have not been able to remove my debt. I am joining the armed forces and must get this issues rectified, I am in desperate need of help. My part-time job is not enough to support and pay this debt in full.