I need some help

I think I may be finally getting out of a 3.5 year abusive relationship. It's taken everything in me and so much strength but I'm moving forward. Only problem is, he owes me almost $4,000. (His car was repossessed and I stupidly gave him the money for it, and I paid for my own engagement ring and he was paying me back monthly, sooo unbelievably stupid I know but I've become so weak under him. His credit is bad so I put the ring under my name. He made me think we had to be engaged to be happier.) anyways, how do I go about getting that back? I'm sick of staying in this relationship to get my money back and I've had enough. Thank you.