Hi Harrier, I don't have any experience being in a marriage where there's been an A, but your behavior is reminding me of how I was acting last spring. Our M was in serious doo-doo at that point; I was seriously considering leaving because of the extreme emotional distance, crappy communication and some increasingly poor treatment from my H. My IC finally got me to start putting my foot down and initiating and asking for the changes I knew our M needed. It took a long time but my H started following my footsteps and working towards better connection etc.
Much to my surprise, I started doing similar things to what you're doing now. The way my IC described it was it just boils down to resentment. You're still hurt. When you say things like 'you don't really want to try to work things out, do you' - that tells me you're still scared and untrusting and you're kind of asking her for reassurance that she DOES want to stay and work. You're still grieving what was; unsure and afraid of what will be; and, frankly, you're still likely pretty angry. It's ok to be angry. But those huge feelings are likely what's preventing you from 'following through' as you say. Sounds like all pretty human emotions to me.
My best advice would be to not hate yourself; try to forgive yourself your actions, your words, instead. You're worried about not giving her a stable, loving guy at home, but it doesn't sound like you're doing much to show that guy much love yourself. (sorry if that sounds girlie... I'm a girl...can't help it!). I think if you ease up on yourself; stop fighting your feelings - the key is to write them down and get them out of your head so you don't vent them on your wife - acknowledge them; accept them, and accept yourself. I think it's then that you can go to your W with a clear head and manage the bickering a little better. And good grief! Bump up those MC sessions. I see my IC once every two weeks. Draining my savings but saving my brain and heart.
Thinking good thoughts for you. Remember to forgive and accept yourself. You're a good guy. You deserve to be good to yourself.
I cannot complain for not receiving from others, that which I've never asked them for.