She's in MLC, but I was weak. Now what?

[crushednstuck]

After reading some fantastic posts and taking away some useful ideas, I need to start a thread of my own in order to get some help with my sitch.
I'm a northern product of a Southern WASP upbringing. I was raised to not talk about family money, dynamics or emotions. My dad was gregarious and outgoing. I probably inherited some self esteem issues from a more reserved and anxiety-filled mother. I've spent the last 35 odd years trying to fill out a six foot plus body while shrinking at being stared at as one of the tallest in the room.
My wife is Irish and Italian and heavily favors the latter. At 42, after three pregnancies she's still hot, though she complains about her weight which has gotten away from her a bit. Her parents separated when she was about my daughters age now. It was vocal and uncivil at times. I think she picked up some major control issues as a result.
She says she began her A with OM in August 2009. I was crushed. Refusing marriage counseling, she says she needed space and more emotion from me. I process info very deliberately and don't typically overreact - by training. However, after fairly successfully filling out my frame, I was more than prepared to exact revenge on MF OM.
W started showing openness after several months, but has not given up OM. She gets pissed I don't show her more emotion during this period and states it's no different than when married. I detached and showed her little for some time. This only upset her further.
Our limited self esteem / control issues paired well for years until her bossiness started pushing me away and I either ignored her or adopted passive/aggressive coping. In conjunction with our lack of communication, we experienced my 12 month unemployment at the time of my daughters birth. This immediately followed a horrific miscarriage. My son arrived as we were building a new house and she temporarily lived with her folks and me with mine. Due to finances we put our kids in the care of my rapidly deteriorating alcoholic mother and absent father - turns out he's carrying on a four year affair. He dies in 2007 and catapults Mom in with us, accelerating problems with W.
I've done fairly well putting anger away, but frustration exists. Eight months after her bomb, I have a one night stand as some attempt at building self esteem and immediately regret it. Of course things begin to thaw a bit. She's uncertain about OM and me. We have good days together with the kids-as family, but she blows up at night. It's a weird routine. She moved out in February, but invites me over for dinner. Nice, then explosion. She then starts hammering me about "honesty" as she tells me neighbor (sheriff) has been harrassing her for months. "Patrolling" by her new place and pissed he wasn't chosen over OM. All the while he's my buddy. Out for beers, etc. More betrayal and drama. We unite against him, his crew, but it's not good enough for W who's still hammering away at my "relationships".I know she's trying to feel better about her A. I have nothing going on but have texted and met a couple women for a beer, nothing else. I drop my bomb Monday night after she asks me directly about the trip I met my fling on.
I know..two wrongs and all. But the loneliness, and uncertainty got the best of me. Now nothing. I want my W and marriage, not a new R. She's still with OM. What next?