What do you do when a friendship has gone straight to hell?

So me and this guy used to be like bestbestbestbestbest friends. We dont really see eachother that much so we pretty much just text/msn/facebook and stuff like that. So we used to be like so close you have no idea. We told eachother absolutely everything, and after like 6 months of us being that close he started cheating on his girlfriend with me and stuff, i dont want to get into that, im just trying to say that we were really, really close. We were dependant on eachother. So i did a couple of things [I did NOTHING to him. It was stuff that dident concern him.] and the only reason he got kind of mad about the things was cus he would tell me oh dont do that and i would do it anyways. But like i said they had nothing to do with him. And ive apologized a million times for not listening to him, and i told him im not going to do anything stupid, he was right and i should always listen to what he sais because hes alot smarter than me. but weve just changed. well actually, he did. One of the things i did made him so mad at me he ignored me for like a straight week which killed me because im kind of inlove with him [that really dont matter tho] and its like ughh :/ and i remember i dident answer him for a day once and he was texting me over and over because he was sad about it. I keep asking if we can go back to normal and stuff because i know that things between us would never be awkward, its just that hes being so distant. He hardly answers me and when he does its just.. not the way it used to be. I really need us back because he makes everything okay, i cant count how many times hes made my mood go from horrible and crying to full out grinning and laughing. I need him. I just dont know what i can say to make things better. I mean we used to seriously talk all day, everyday. Id wake up with morning texts from him. We had like our own things, like when we went to bed wed say goodnight with a "E> " kind of heart instead of a normal one for no apparent reason lol and even he called us bestfriends. and just ughh i miss him so much and i just need advice on what to say to him to maybe make him be my best friend again