Thanks

I am getting conflicting advice from friends about this issue. I am hoping somebody can end my confusion. A couple of weeks ago I took my Mum out for her birthday. Another driver scratched the front passenger side near the bumper of my car as it was parked up. There are no dents just quite severe paint work damage. He scraped his car against mine. The other driver drove off. Luckily there was 2 witnesses who got the other drivers reg number. Cut a log story short the other driver said he didn’t realise he damaged the paintwork on my car. He has however admitted liability. His insurance is paying out. Last Thursday my car was taken away to have the paintwork done. Today I been told my car has been put down as a total loss (not a write off). As it is only paintwork damage and not body work or mechanical damage, I don't understand why it has been put down as a total loss. I have been told by the insurers I can either write the car off and receive payment to the value of the car or I can take a lower payment and get the car repaired myself. I am getting conflicting advice from friends. Some are saying if I keep my car and get the repairs done myself the car will then be classed as a category S or category M and I will no longer be able get insurance on the car as it will be classed as written off. As it is only paintwork damage and not body work or mechanical damage, I don't understand that. My questions are If I take the payment to get the paintwork repair done myself will I still be able to insure my car when the insurance is up for renewal? If I take the payment to get the paintwork repair done myself will my current insurance policy be voided? If my car does get classed as category M or S will the stop me from selling it on the future? Thanks