Can you ask him to be specific on the things he dislikes, if and when the conversation comes up?

I think you're trying to rationalize a lot of irrational behavior. You really are observant and have pinpointed a lot of the issues. But I think the responsibility/perceived burden is what is blowing this up. He can't handle it. Doesn't mean he won't down the road. But he's not handling it now.

Are there separate issues with you unrelated to the pregnancy? Hard to tell. You mentioned not being the most attentive wife.

Have you guys done any MC? I think a lot would come out there if you find the right MC who can facilitate discussion and see what's happening with him from a mile away.