The one day I chose to take the Lemans to work before a week's vacation I hit a deer at 75MPH.
It sucked and took the wind out of my sails as that was a car I'd had for 14 years at the time and driven everywhere with zero issues. Bent the frame and every panel up to the cowl. I still haven't recovered.
That said, it's just a car. You put a ton into it, but your son at least is still alive and I guarantee he feels just as bad if not worse than you do about it. I know how bad I felt over it being my car, I can imagine how bad he feels over someone else's.
Give it time, don't make any rash decisions.