Laws vary from state to state and your question left out a lot of important fact information; so I can only give you general information. I am not qualified or licensed to give legal advice outside of Florida.
Assuming you are just trying to have your vehicle repaired: If you have the necessary insurance coverage, they will repair your vehicle and should pursue the responsible person. Make sure they recovery your deductible for you. If you do not have collision coverage and the amount of your loss is not enough to hire an attorney, (in Florida) you have a right to represent yourself. The clerk’s office of most County Courts will have forms and instructions available for you to sue the responsible person. Check with the Court to see what type of witnesses, you must bring to the trial (example: the body shop estimator to testify about the amount of damage to your car). If you have insurance, but they are denying coverage, I recommend you consult with a licensed attorney in your community. Suing your own insurance company over coverage, will likely involve specialized knowledge of your states insurance laws. Important, do not act out of emotion. Be sure the damages are enough the justify the time and money you will spend suing him. Even if you can get a judgment, think about your chances of actually collecting the money from him. The laws on collection vary greatly from state to state. IMPORTANT: If he is charged with a crime, for the DUI and/or theft, the criminal court may order him to pay you financial restitution. Check with the State Attorney about how to request restitution. That may avoid the need to sue him.
Again, there is a lot of information missing. I hope this was somewhat helpful. If you can not afford an attorney, you may want to see if your state's bar assocaition provides free legal advice or services.
Mr. Groff's suggestion regarding restitution is probably your best bet. Hopefully, your ex has been charged with a crime and has not yet been sentenced. If so, then go speak with the prosecutor / district attorney immediately about restitution. You should take the repair estimate or the actual repair bill with you and give a copy to the prosecutor.