Hi Bella,
My question is, Did you offer money for the repair of his truck? It is just fair for you to do that. At least he will know that you a responsible person. If he wrecked your car, probably you will expect for him to pay for the repair of your car. Being boyfriend and girlfriend here does not preclude being responsible for ones actions.
Ones car is an extension of oneself, at least that is how I look at it.
If you pay him for its repair, then probably he will feel better about you.