Why do you think your actions on the 22 actually backfired? The first thing you have to accept in this....if you make plans pertaining to your husband expecting a certain reaction, then you are off base a bit. You make plans to improve yourself, 180, GAL, or whatever....not for a reaction from your husband. In improving yourself you find your old self that isn't filled with hurt and anger and become stronger, more confident, more sexy, more appealing, and more emotionally stable. Don't make plans expecting a reaction, it will almost always backfire.
I will disagree with Rob about the children. You set a boundary by telling your husband to return the kids due to their sickness. Children shouldn't be getting moved around from house to house even if it is just a bellyache. Regardless of your relationship with your husband....the children's welfare needs to be protected. Their well being has nothing to do with what is happening.
On to the 22....backfired...yes...because you expected results. From my seat it worked quite nicely actually. You were out all day and then came home and informed him that you were going back out. His reaction was predictably negative, but that is the reality he created. You are going to have a life, things to do, and obligations that need to be attended to....no longer is his happiness the center of your existence. He doesn't like that! On his end that is just the beginning of what is in store for him on the path he appears to be choosing. Next comes divorce and childcare payments...he isn't going to like that. Then comes you seeing other people...he isn't going to like that. Then you will introduce the children to another man...he isn't going to like that. Do you see a reoccurring theme....those are the consequences of his actions...period. You gave him a very small taste of that.
You are on a long road...so patience needs to become your ally. You may think this happened over night, but it has been in your husband's mind for awhile. Now is the time when you get to start playing catch up. You WILL heal....the pain WILL go away....you WILL survive. What you will find through DB'ing is that you will make the steps towards healing much faster than most other routes. Focus on yourself and the faster you do that the better you will be.
As far as the back rubs, ETC.....He is a guy. I hate to be blunt, but you are there and he is willing. To most guys in affairs it doesn't matter where it is coming from, just that it is (example-In my wife's first marriage she had an affair with her BF's husband. Down the road come to find out, there were 4 other women not including the BF). In other words...cake eating. With woman WAS's there is very little actions like your husbands, but with guys.....two is better than one. Males and females do operate differently......shut that door for him and he isn't going to like it (the theme again...LOL).
The first step towards saving your marriage is finding yourself.
