How Do I Get My Car Back from ex Boyfriend?

I signed the title over that is it. We did not do a bill of sale bcause he agreed to pay 1000.00 for the car and has not. I left the plates on the car, my bad and I am not sure if he has done anything to transfer car if he has he foriged my name to a bill of sale. I want my car back i have keys can I go get it

Get Your Ex Back