If I felt like we had to address the past issues as well, I'd be completely overwhelmed....completely
Not that I want to overwhelm you, but you are going to need to address some of those past issues if you want to improve the M. You can't just start with a clean slate. The two of you have an established pattern of interacting and you will BOTH need to change that pattern if you both want to end up happily M.
I bring something up, a fight ensues, and H ends up angry at me and I'm angry at myself for not leaving well enough alone.
You are directing your anger at the wrong person. This is going to lead to tons of passive-aggressive behavior, depression, and another possible A. It seems clear to me that until you start asserting yourself with him and stop LETTING him "win" the fights all the time, you will get no where.
So, you're saying that you think I should or should not pay more of the bills?
I'm certainly not going to tell you how to run your finances. But I just know for myself and H, the "you owe this, I owe that" mentality was not helpful in making us feel M. We have a joint account and all the bills are paid out of that account. It is "our" money, not his/hers. This takes the power-play out of it. Is there a reason you are opposed to joint account other than you've just never done it that way?
As long as he doesn't feel like we address his 'issues' more than mine, I think we are actually doing pretty well in the MC sessions.
 Ok, as llong as you address each other's issues equally. You should not be the target of the C and neither should he. But his eye-rolling behavior says a lot about his views on C and his ability to actually change is you ask me. Just be careful he is not doing it just because you want to. My H and I wasted about 4 months in MC when his heart/mind were just not into it. And trust me, he said all the "right" things in the sessions but it did not translate into real life until HE was truly ready to take that step. Again, it does take TWO people to make a M work. And we wonder why the D rate is so high?
I cheated on the man. He doesn't want me in the marital bed. Don't I have to respect that? How can I expect him to ever honor my boundaries if I refuse to honor his?
It sounds like you are willing to put up with way too much sh*t seems to me. That is like my H saying, well, I left her so she can treat me like crap and punish me for as long as she fells is necessary. I know perfectly well that is not right but I don't get the sense your H sees anything wrong with how he is treating you. And that is the problem. He treated you badly before and now he has an excellent reason to continue this poor behavior, the A. He is going to be firmly entrenched in his belief system of entitlement - UNLESS you break that belief system down. You cannot do it totally on your own, without his help. BUT you can start telling him (maybe with the MC help) that the time has come to either sh*t or get off the pot. I will be sleeping in our bed again. I will be buying clothes as I see fit. I will be.... If he starts to learn that you will not back down (your typical pattern) he will respect you more in the long run. Neither of you seem to have respect for each other at all as it stands. Start there.
He shows me what he wants me to see. He doesn't want me to see the real stuff. The hurt, the fear. So, when I do things that press those 'buttons' he hides his reactions so I don't know what causes them. Same with me trying to affect him with a boundary or a change...he will hide how he really feels and show me only what he wants me to see. Such as him whistling so it appears he doesn't give a flip about what I may have said when inside, it really turned his stomach. Does that make sense?
 Well, he is in major denial mode. It is easier for him to show anger than to show hurt. Clearly he is not ready to "go there" yet but he will need to go there eventually or you'll be talking to a brick wall the rest of your M. H sounds very emotionally immature. Does the C call him on any of these behaviors?