usually i would say with cheating that it's a hard thing to get over. however i think that you have been together so long and it would be a shame to chuck something away over a few kisses which is obviously regrets deeply.
but it is going to be very tough... do you think you are strong enough? because if you will be left for months at a time wondering who he is with and what he is doing then it will end up eating you away.... and potentially you could end up accusing him of things he has not done because you're paranoid.
i think you should have a good think about if you can 100% forgive him and know that it won't be an easy road ahead. but just remember.... he was honest with you. i think that was a good thing for him to do, a true cheater wouldn't confess like that.