BG, are you serious right now? The A was a savior? A shining beacon in the blackness of your marriage?
If your husband has broken every single marital vow, then why in Grimm's name would you R with him? If he's such a burden, not much of a man, and such a jack-off, why stay? Surely your AP was all that and a bag of chips? Your AP was the one that showed you "intimacy" and what a "real" relationship is like right? Or at least, that's what you're saying. So if your AP is the one that "enlightened" you to new and wonderful things, why not just leave your deadbeat husband for him? It seems, from your description, that the AP is the "better" man. Oh wait. You love your husband right? You cheated on him because you love him...
It never ceases to amaze me how WS will justify every angle of the A. It's always the BSs fault. Always. They don't want enough sex, they want too much, they aren't adventurous enough, they're too adventurous, they wear flip flops, they snore, they watch too much T.V., they don't do enough household chores, they don't make enough money, they make too much money and are away from home too much, they don't plan enough vacations, they don't talk enough, they talk too much, they aren't creative enough for holidays, birthdays, and special occasions, they're too creative for holidays, birthdays, and special occasions, the BS is depressed, the BS is cruel, the BS is emotionally cut-off, the BS is a jokester, the BS is a douche. Shall I go on?
Look, I get it. There are some people that are very hard to live with. (Whether BS or WS) Some people are mean by nature. I know a woman that is a real witch. Like seriously. Nobody likes her. Does she deserve to be cheated on? Nope. Her husband still has options. But he stays for the classic, "We work it out for the kids" crap. Yeah, they're not working it out for the kids. They are in complete dysfunction and passing it on to the kids. Their kids have no clue what a healthy relationship dynamic is because all they see is chaos and that their parents are "trying". (If you call resentment, zero intimacy, fighting, backbiting, and a "You-do-your-thing-I'll-do-mine" attitude "trying")
No person deserves to be cheated on. EVER. For any reason.
Can a relationship heal after an affair? Yes. Can a relationship blossom into something it's never been after an affair? Yes. But to claim that a marriage benefited and was "saved" from an affair!? Not hardly.
Do BSs have problems they need to work out? Yes. Is cheating a way to get them to do that? No. What happens if the reverse happens? You cheat, and they get worse? Because they are already struggling with FOO and whatever all else, and you just piled it up on top of them. Why the heck would you risk that!? (Because you state he was a jerk already and you "couldn't" leave the M) What would have happened if you'd cheated and it was a dealbreaker for him? You damaged him further and nobody is "better off".
Does my husband have problems? Yes he does. (I do too.) Is it my job to make sure he addresses them? No. That's his job, his choice. He may or may not work on them. Doesn't give me a right to cheat on him. Doesn't give me a right to abuse him and tell him my A was HIS fault because he couldn't get his act together. I'm a SAHM. Leaving would have been very difficult. But it still would have been better than cheating on him. Even now, there are things that need worked on. At the moment, he has no interest on digging in. I have to decide how to react to that. Do I get pissed and cheat again? Or do I sit back, be patient, encourage him, and support him and come up with a game plan in the event he never does? I have options. I'm exploring them. Cheating isn't one of them.
Stop justifying your A. It was wrong. Don't care what excuse you come up with, or what color airbrush gun you use to make that excuse pretty. If your BS is a pain, leave. It's really that simple.
What I see is that you have demanded that your BS change to make you happy. You cheated, blamed him for it, and expected him to change in accordance with your "standard". Pretty sad really.