We don't know your H and you do. I saw a lot of sense in your reply to Puppy.
I agree totally with him that you should perhaps not be directing your actions at OW and OWH but rather you should be looking at the things that trigger your H to feel entitled to act like he did when he didn't come home.
Alcohol seems to have a large part to play. I don't know if he needs AA as it seems that the drinking has been a relatively recent thing and seems to go hand in hand perhaps with a bad conscience. Getting him to stop drinking may well be a big factor in stopping him seeing OW - we all know that alcohol stops us feeling so inhibited and makes us do things that maybe we wouldn't have done otherwise.
Also, the children are of an age where they don't need babysitting all the time and perhaps you should start going out and enjoying yourself more.....and see if your H would go with you - try and remind him of the old times.
Most couples get bogged down in the raising of children and it is common to lose sight of one another, and forget why you decided you wanted to be with your S in the first place. Your H needs reminding.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength