How do I get out of my car?

I wrecked my car 2 years ago and totaled my car. The day I totaled it I was switching over to another insurance company so I did not have insurance. Stupid move on my part I shouldn't have been driving it without insurance. but that isn't the point. after two years of paying 500 a month on a totaled car I finally got the oppurtunity to fix it. I did all of the repairs myself, I'm an autobody technician. Now I've been trying to trade it in but I owe more than the car is worth now. My father has perfect credit and tried to cosign a loan for me, my credit is 600. I had 1500 of negative equity that would have been applied to the loan. They will not give me a loan even with a co signer. what do i do?