Please help, what to do in a car accident.

Was involved in an accident, driver side swiped me on driver side while i was on left lane, no other lanes on my left. Driver tried leaving the scene, i followed, went through various sites, when turning he suddenly stopped and braked i hit him on side of back bumper. Three witnesses at scene. Driver was arrested, DUI, leaving the scene, tag suspended, etc. Driver has a horrible insurance company, takes too long to pay out, i called my insurance, they said the accident was actually two incidents and making me pay out 2 deductibles, they said they have to review the last incident where i impacted other driver, might put me at fault. I was not at fault have witnesses, and I don't want to loose one or any deductible for someone else negligence . How should i proceed, sue my insurance, the driver, or his insurance company? Should I sue in a small court or somewhere else? Should I sue at all? Is it worth it? I have lost my financial stability was planing on buying a house. A little lost.