MS, I can completely relate to where you are at right now. You are stuck between feeling hopeful/wanting things to be better and the reality that no, you are actually just stuck in an RV with minute-to-minute reminders of what is wrong. It is SO painful, SO heartbreaking, SO hurtful. So many hugs to you right now. You are not alone.
I don't remember which thread I read this on, and I am going to probably mess up on the exact words, but someone asked another person whether they were in love with their spouse or in love with the idea of their marriage. This stood out to me and during some tough moments I have really had to ask myself that question... am I really in love with this person who is hurting me so much? Am I in love with the 'old' them (who likely is not coming back in the same form even if we do work things out)? Or am I just really in love with the security and stability that our marriage brings to my life and my family? I don't have the answer for myself here, but asking myself that question often has helped me get my head just enough above water to catch a breath and keep moving forward in that moment.
And as hard as it is, we are all just putting one foot in front of the other. That is all you need to do. One step at a time. It can be tiny, you might take a few steps back, but just keep lifting that foot and placing it in front of you.