You did do the right thing, don't worry. Its down to you and your boyfriend to sort it out now really.
I could sympathise with you if you were drunk, coz I sort of did the same but I had no control over my actions, you sound like you did. Me and my boyfriend got through it. However it will put a little strain on the releationship in terms of trust. He should trust you, just not when your out again for a while. And if he really loves you too it will hurt, from both perpectives.
Also, if you feel this bad, you won't do it again, and will make sure of it. What i mentioned about happened early april, and I haven't been out with my friends since in fer of doing it again. Next time I'm out drink my boyfriend will be there.
I'm giving an example of how it might be.
Anyway, just explain your sorry (you might have to do this many times) explain why (you might be asked) and be aware that he might be angry.