Boyfriend gets mad any time I speak to the opposite sex

My boyfriend is extremely jealous and I'm not allowed to talk to anyone of the opposite sex. The only time he's kind of okay with it is if it's at my job.

Last month a man came in maybe in his 20s extremely intoxicated. I told him we can't serve him more alcohol because he's too drunk. He got mad and hit me in the face. Mind you I'm a 5'1 girl. This man is at Least 6'3. We had to call the cops on him. It was awful. I pressed charges for assault and my boyfriend was very supportive. What he wasn't supportive of is in court where the man plead guilty to assault he wanted to apologize to me and my boyfriend didn't want me to talking to him and said I should have no issue with it since this guy hit me in the face which broke my nose. So I never spoke to him. His friend or brother or whoever came to the restaurant and gave me a letter from the guy. He was apologizing and said he comes from parents who are alcoholics and he thought he would be different but it's clear alcohol isn't for anyone in his family. That it's not an excuse for his behavior and he's so sorry. Said he realizes now that he needs to get help. Yadda, yadda, yadda. Anyway. All i did was tell the friend or brother that I forgive him. Well my boyfriend is mad about that and has decided that I knew this man or something and that's why he hit me in the face. Insinuating I'm cheating. I can't win here