How to get car back? Sorry to use English. Need help

I (a man) and my friend (a girl) own a car togather. I am the 1st owner and she is the 2nd owner on title (joint account). She use it all the time. She paid the down payment and I pay most of the loan monthly payment.

She does not answer my call and email. she still use the car but refuse pay any monthly loan payment (the loan is also under two name). To protect my credit, I continuesly pay the loan.

Please help me to get the car back or any suggestion. How can I sue her. The loan is more than the small claim court judgement ($5000).

I live in Texas.