My mom is so critical that I'm already regretting moving in to be her caregiver.

I also had a mother like that. We lived across the street from each other. I moved her to my city so that I could take care of her. She would complain and I relate to all the things you say. It was worse when people visited she really acted out.since I did work I was gone most of the day and only visited before and after work thru the evening. We had agreed before the move that she would have her own place, actually she insisted! She had similar medical conditions plus COPD. She was in my care for 5 years. It was the hardest thing I have ever done. My sisters both lived out of town but came when they could. Since I was her Durable Powere of Attorney for Health Care, when she criticized me or acted out in front of people I would say: mom, I think I would be careful what you say to me considering I have control over your end of life care and decisions.... I was able to be off work for the year before she died. As she became more and more dependent on me, she changed her behavior toward me and I saw her becoming more frail and vulnerable. I cannot tell you that there were not times that I wanted to pull her hair out or scream, BUT, I did learn to say that I was not going to stay with her while she talked to me like she did, I would preface that with telling her that I would always be there for her until the end no matter what. I just told her I was going to leave if she didn't change her behavior and comments. She could really be rude, condescending, and just not nice. I hope this helps you in some small way. I will say that I am glad I spent the time I did with her and would do it all over again.