I got into a fight with my roommate at school, how do I fix it?

A couple of weeks ago my roommate who is also my bestfriend and I went to one of our friends house for the weekend. At out friends house, my roommate got completely drunk and disrespected me and went to hit me. I told him about it and he apologized. Then when we got back to the dorms that sunday night everything between me and him were fine. He plays world of warcraft and that monday it the new expansion came out. He kept on playing it until 5 in the morning and i asked him to stop because his clicking on the mouse kept on waking me up. Then we got into another fight about him playing world of warcraft, but that fight blew over also. Then last week he was drinking in our room and he got a little too drunk. I had left the room and unpropped the door to the room b/c i was leaving to drive my friend to work. My roomate then called me up and was very upset with me over the phone b/c he wasntin the room when i unpropped the door and he got locked out. I told him i would be back in about 30 mins to unlock the door. Instead i came back sooner and unlocked the door and he got mad b/c i didnt tell him right away. Then later on that night we got into a huge yelling argument. Then I talk about him playing world of warcraft and i say to him, "if you keep playing world of warcraft until 5 am, then i am going to tap my keys on my desk while you are trying to sleep." Then he says to me, " if you do that, then im going to take a certain object and push it up against you to make sure you dont do it again." The object he was referring to was his pocket knife, which is not allowed in the dorms. I went to the resident advisor and told the resident advisor, who told the resident director. The resident director made me move out of my room and cut off all communication with him. The next morning i felt aweful about what had happened b/c he had gotten in big trouble b/c they found his pocket knife when they searched the room. I had told one of our mutual friends about the situation and he said i was probably more wrong than my roommate b/c i knew he wasnt going to actually go through with the threat. I had felt completley aweful about what happened. I felt so aweful that my friends thought i was going to commit suicide so the resident director called 911 and made me spend at around 12 hours locked in the psych ward at the hospital. After I was released, the resident director made me move out of the dorms. I then wrote my roommate a 4 page apology note and told him that i was sorry about everything. I didnt tell him though that the reason i got locked in the psych ward was b/c of what happened between him and me. He is still mad at me and doesnt want to be my roommate anymore once i get cleared to go back to the dorms. What should I do to get our friendship back, him and I were best friends and now we are not. I feel like everything that happened is my fault. Also the school is pending him for expulsion due to the threat and him having a weapon. What should i do or say to get our friendship back and make him want to talk to me and be my roommate again?