That strut tower crack was 100% from the collision. You would have felt it earlier on track if it was there.
You have really stiff suspension, with regard to what came on the car from factory.
Add up all the torsional strain from all the G's you were pulling all these seasons, and its no wonder you got that crack.
You could whine and cry about it like a good Honda kid. Or you could find a shop, that can weld it back together, maybe even add some support/reinforcement plates to both sides since you have now discovered a weak spot in the chassis.
You can either grow from it like a good driver, or cry about it, sell the car, and go back to daily driving boring grocery carts until you grow old and die.
Im rooting for you, even if it is a Honduh.
Edit: You could also use this as an excuse to upgrade some bushings on whatever suspension you transfer over.