I agree with someguy0000, you must not be so hard on yourself. And some people on here need to realise that these things happen, not everything is so simple and the world can not be divided into good and bad people.
You just need to tell him that you need it to end. You don't need to tell him about the other guys, unless he is likely to hear it from someone else, in which case it is best if you tell him everything. There are obviously issues in your relationship that prevent you from being completely happy, but not telling him about the cheating does not constitute lying. Just do it soon, so that you can both move on.
Good luck
x