I am sorry about your relationship with Robert, but I have to agree with what Shezbut that Robert may be a drinking buddy and not such a healthy friend. Of course, I don't know that, but based on what happened, it really sounds like that. Maybe it would be best to distance yourself from him. Maybe still communicate with him, but not as often and not in the same way. Change your activities together and see if he is willing to still be your friend when you are both sober. Or maybe you should just take a break and see how things go.

It worries me that you got in the car with him while he was driving drunk. He does not think it is a problem to endanger himself and everyone else on the road with him, not to mention all of you in the car with him. I know we all do things hat are unwise sometimes. I just wonder if Robert is really helping you to be the best you possible.
That is for you to decide.