My mother is stressing me out HELP

I am 25 weeks pregnant, married, and have 2 young children already. My mother and I used to have an okay relationship before. She is a very negative person: she acts like a victim a lot, complains all the time, and she is only (somewhat) happy when I am doing something with her.

Me and my husband live with his father. We have a separate basement, but we see him every day. Not long ago, we went to the zoo and he came with us. My mother got mad and told me off. When I usually visit her, the visits are only about the grandkids and her complaining about her health issues or the fact that she doesn’t speak English. She also loves complaining about my older brother who has a lot of issues such as being able to take care of himself as a grown man would (grocery shopping, keeping his money to pay bills, running errands such as renewing health cards, etc).

Anyways, about a month ago I invited my mom to go to a Hungarian festival with me and my husband. A week beforehand, I had to cancel due to an argument me and my husband had. My husband’s mom invited us to go and spend the weekend with her. Her sister, my husband’s aunt, is dying from cancer and my husband hasn’t seen his mom outside of the hospital (where his aunt is living now) since May. Also, this weekend we had a heat warning. I am pregnant and have spd which means I can’t walk for too long without being in pain. So after an entire day of arguing, we had decided that we will go to my mils. (I also asked my 5 year old who she wants to see this weekend, and her answer was to go see my mil).

Now, my mom is making me and my husband feel bad because we canceled on her a week early. She was being pretty rude in her texts saying thank you for the nice weekend and that she did not need any help. My husband told her that his mom needed his support due to her sister dying from bone and stage 4 lung cancer. My mother ended up going to this event anyways with the people she invited without my knowledge that they were invited anyways. (I have never met these people and I told my mom I have no intention of meeting them.) Also, her boyfriend was there too whom I do not like because he likes to make shitty comments about my husband and sometimes my mom as well as he “checks out women” in a disturbing way. I told my mom I rather not go with them because I do not like this guy. (He ruined my wedding and acted as if I invited strippers to my gender reveal not long ago - so I kindly told her I have no intention on having any sort of relationship with him anymore).

I do not do much with my mom because she works unpredictable hours, I have two young kids at home and I am pregnant. however, she does not want to acknowledge the fact that I am my own person and can decide where and what I want to do. I feel like I need to tip toe around her because she gets mad over everything. What should I do? Or what should I say to her?