I have been wondering / feeling similar things, and I think is just yet another stage of this to get through, which could actually mean "progress" ultimately. (Though that sounds funny) It is truly scary when we have to acknowledge that even though we are doing all we can to save our marriages, we also have a breaking point, too.
I am nervous about giving any advice, but I hope you do whatever is necessary this weekend to avoid, postpone, fight off, and extend that breaking point- not for H's sake, but for yours! The resentment is different, though, and has to be dealt with somehow. Vent vent vent! (here, I mean).
Does H really jump on you for backsliding? Or are you putting the pressure on yourself?If it is him- it sounds like you have his undivided attention
