history: I recently cheated on my girlfriend. I feel absolutely terrible. I cheated on my girlfriend recently. I feel horrible about myself right now. Sorry to hear about that.  I wonder if there's any way to fix this situation.  What do you plan to do?
current: I plan on coming clean at some point, but I'm not sure how to break the news.
next: Coming clean is a great way to start.  It's hard since you know she'll be hurt.  Were you having trouble in the relationship before?