Unlikely that you will be looking at jail time unless you have a prior record, but you should consult a local attorney as soon as possible for more accurate advice.
Since you were not ticketed for not having insurance, I guess you have insurance, right? If so, notify your insurance company immediately. They will contact the other driver, and if you get sued, they will provide you with a lawyer. You made a mistake, and those things happen. I'm glad you pulled over.
Hire a criminal defense attorney to fight the charges in court. You put this question under car accident. The attorney that answer are normally PI Civil attorneys, not criminal. You need a criminal defense attorney or DUI lawyer (Hit and Run and DUI go together like peas and carrots.. i know you're not DUI).
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