Hi there I’m a full time carer to my mother who has mixed vascular dementia and Alzheimers

I'm new to this site, so here goes.

My mother is driving me nuts she continually calls out help and it gets louder and louder if no one's in the same room I worry one day someone's going to call the police. Also for the past few days she's been continually argumentative over nothing and blames other people who are not there, she also blames us then becomes verbally nasty to is and goes on and on and on all day. We try to calm her down but most time she only gets worse.
She calls my name for everything because I'm the full time 24/7 carer and always there, which makes the other person who works full time jealous annoyed and angry most of the time.

I feel like I'm going crazy, heading for a breakdown. I am already on antidepressants for a pain condition, and right now I don't know where to turn or what to do and how to calm my mother down when she gets like this, I'd love any help/advice please and thanx