Why does my Mom want no one to visit and wants me to sit and look at her all day long?

Let's start at the beginning here
1. How old are you?
2. what is mom's diagnosis?
3. Are you in her house, or is she in yours?
4. Is she paying you to be her caregiver?

the answers to these questions make a huge difference. Post back and let us know.

How old are you ? Does she still think you are 14? What are her ailments? If she cannot be home alone, tell her either you can have friends over or she is having a sitter for an evening or two a week! Does she have any friends who could visit, or is so.. tell her if you can;t have friends niether can she! How would she like that? I agree you need to assert yourself more, and I know this is hard... But you are the only one who can stand up for yourself. She will get over it after she sees you mean it.. or you have to decide to take care of yourself

It's called manipulation, and it's probably not something new. Discuss the behaviors with her MD and ask if he can run some tests and order the proper medication. In the meantime, draw your boundaries. Go out with friends and ignore her tantrums. Going along with her demands will only make them get worse. If she attacks, call 911 and have her admitted to psych dept.