Clearly you know what you did is wrong, clearly you know what you want....you can communicate these things to your BF every day, and prove to him he is the one for as long as it takes. You can ask him for forgiveness and whether or not he will forgive you.

If it were me, I'd me mad for a while, but the proof will be in your future behavior.

If you think you want to cheat again, don't cheat...remember how you love your BF....