I cheated on my boyfriend, what should I do?

So I asked a ? a few weeks ago about why I would be in love with a guy whos a loser. I've been w/him like 4 years. but we were close friends before that. he has nothing going for him, no job, no money, no car, and has a drug problem. but he has always been good to me and has proven he loves and cares about me
anyways the other night I had sex with someone who I thought was just a friend, but now apparently its more than that. I forgot I was suppose to pick up my b/f and left him with no ride while I messed this kid at his house. even though my boyfriends not good for me and we needed to break up anyways, I feel horrible that this is how it had to happen. I know hes hurt really bad.
so my ? is how can I apoligize and make it sincere? should I call, go to his house, write him a note..? im not expecting him to take me back but I want him to know I feel like sh*t for doing this and that I will still always care about him.

Dear cupcake143,
Sleeping with someone else was a way for you to get out of your dilemma. You are unable to leave him because I think you felt that leaving him for not pulling his weight with a job etc. was not a good enough reason to leave. You actually felt guilty to leave him for that. So when you tell him this he will leave you; taking the problem out of your hands. As I remember he has also just lost his father. I think what you have done was a cowards way out. You would have been much better off to follow the advice given to you on your previous question since you will now carry this guilt. On the bright side you see you are in need of counselling to develop some coping skills and even learn how to have a backbone. I would spare him the news of what you did and tell him that you need to have some distance right now. Time to get your own act together before you get into another relationship you can't handle.
Sue...good luck

just be honest with him and tell him what happened and how you feel about it so you can get some closer ...after you tell him what happend tell him your ready to talk when he is

You already know you guys needed to break up, and despite the fact that it might hurt you it's also your life and your relationship and you shouldn't let him influence what you do.
I realize you cheated with someone else but that's no exscuse either. The best thing you should have done was probably broken up with him. And maybe you could be his friend, since you said that previously worked out. And then the guy you slept with, wouldn't be cheating. I know this is no advice now because the past is the past but maybe you should just emphasize that you want to be his friend.

he might not want to see you so maybe write him a note and leave in like on the door of his house or on his car. and explain everything that happened and that you didn't want it to go that way or hurt him in any way. tell him your not trying to make him take you back but that you were together that long that maybe you could work things out and be friends again.