Insight help after minor accident
 

So I rear ended someone the other day (bad, bad day) and I believe my seat belt pre tensioner went off. As my seatbelt no longer retracts or extends. I also have a dash light (not blinking) of my airbag and a code that says "check airbag system." I am pretty sure my seatbelt will need replacing. Can anyone give me some insight as to where to go next? I don't want to go to a dealer and pay an arm and a leg.