Went out today and on the way back I knocked the wing mirror off down a narrow country lane with houses on with a row of parked cars down the side. Turned around and went back as we were lost anyways and saw the broken wing mirror on the ground but I didn't know which car or what it was I knocked it off on. Mum reckons it was a van that was higher up so wing mirrors not level but I don't know what it was. The wing mirror has come clear off so it looks like we got the worst of it but we were on a very busy narrow road so I had cars behind me. Managed to get home safely and after reading things online about people getting arrested, fines and courts I'm now panicking! After having had aggressive driver behind me the other day I'm now getting frightened to drive.
I've read so much conflicting reports online(report to police= get arrested/don't report=get arrested etc )of what to do now I'm worried! 
Anyone who can advise on here? 