What you do depends on how the insurance companies decide to resolve this. You'll either get an offer to repair it or an offer to total it. If it's totalled, see if you can buy it back for cheap and keep it as long as you can for parts while you shop for a replacement. Keep what you need to enhance the replacement and sell off or junk the rest.

There's no decision to be made at this point. Pour ALL your energy into establishing what is fair compensation to you. Seek and save ads that describe cars in similar condition, dig up receipts of everything you've done to the car and receipts from prior to your ownership, etc. You'll need this information to rebut the low trade-in value you'll be offered to walk away from this car.

Good luck.

Sixto
95 S420
87 300SDL