Mom is declining rapidly at ALF and I'm finding I don't want to visit. Any advice?

Hello. My mom has Parkinson's and Dementia, and late last year we decided to move her into an ALF memory care facility. She had been doing very well and was quite content until she fell two months ago. She broke her pelvis in two places, and after hospital and rehab, was finally able to come back to her ALF (she was gone a month). It's now been two months since the fall, and she's declined rapidly mentally. She is speaking in complete jumbles and I can't even make out what she is asking for or talking about. She has become aggressive and frustrated and incredibly anxious, which are all things she never really did before the fall. I've talked in depth with the staff at the ALF and they believe it's partly because her dementia is progressing, and partly because she now cannot walk without assistance or supervision and is frustrated by this since she was incredibly active before the fall. I can accept all of this... but my visits with her are just miserable now. Just today I went to visit, and when I came in they had her at the nurses' station and were trying to calm her down. Apparently she was trying to get up out of her wheelchair and walk on her own, then started screaming at the nurses and aides when they asked her to sit down. They were relieved I came because they thought I could console her. Well, I couldn't. She was just as grouchy with me as she was with them. I must have asked her to stay in her wheelchair two dozen times. She says, "I am." She says it while she is standing! I got her up multiple times and helped her walk with the walker... problem is she didn't want to leave her room, so we walked in circles. I was becoming increasingly impatient, but I kept my cool. By the time I left after two hours I was the grouchy one! I had to pry her fingers off of the ledge outside of her room to get her back to the nurses' station since she can't be left alone, and I left the place miserable. God Bless those nurses and aides.

I am not even sure what my question is really. I think I just wanted to vent. I almost feel like I don't want to visit (I usually go twice a week for three hours each visit), and I know some people visit more, some less, depending on their situation. I'm feeling I'm not handling this rapid decline very well. My mom doesn't remember I came, and is angry with me while I am there, and I can't even carry on a conversation with her, but I feel guilty if I don't see her.