He already forgave me...how do I forgive myself?

Back in September I told my FWB (friend w/ benefits) about an incident that occured back in March. I went out one weekend by myself and met some people, but I quickly became so drunk that one of the guys called me a taxi to get back to the hotel I was staying in honestly thinkin he was being a Good Samaritan. However, I don't remember myself giving consent to him to come to my room and it went from putting me down on the bed so I would recover, to mouth and hand action ( or in baseball terms, third base). Needless to say that it was definitely a close call. I told him b/c the feelings between us were getting stronger, and I didn't want this to sneak up again. After telling him that it was a close call he forgave me, but also said he had rather not have known. It was enough for me to hear, but why can't I seem to let it go since I was not his GF and I did not intentionally brought on the situation since I was drunk 4 the 1st time? And how can I forgive myself? Please help me!