Helth Cover

After an accident were someone ran into the back of my car, and left my daughter and myself with minor whip lash and lots of aches and pains this is nearly a week ago,the 3rd party didn’t stay around, and we have no details of them ,police informed but no trace of them, right my excess on my insurance is £400 if i use my insurance to fix damage (900pounds to fix) as this is my first year of driving what will i loose ie no claims and will my insurance be more Next time accident not my fault at all by the way, no minster law are per suing a medical claim for daughter and me, and should be able to claim back cost of repairs but can they when no 3rd party details,should i use my insurance or pay out of my pocket, never had to go through this this before its a mine field! can any one help me understand the procedure of this claim,lost hurt and worried. thank you fro your time