Why is my mother like this?

So when I was a kid I spent every weekend and my grandparents so my mom could go out and party. (Me and my two brothers) my grandparents created most of my favorite memories while I hardly have any with my mom unless they were bad ones.

My mom never spent time with us and stayed in her room our whole childhood.

Now that I have a son, she acts like “babysitting” him is a problem. She calls it babysitting for one. Which I do not like.

She holds him against me. Uses him against me. She won’t watch him for me when I need her to, if she is mad, wants something and I won’t give it to her, etc

She also still screams at me and treats me like I’m a child. I’m 26. She says that I can’t treat my mother like I do blah blah blah. She just basically just tries to control me with her excessive screaming and horrible control she has over me and everyone else.

She has screaming fits when she doesn’t get her way.. I mean SHE SCREAMS, she has broken dishes before, thrown family pictures off the wall, left in her car for hours without answering the phone, etc

She is still like this and always has been.

Why is she like this? I don’t understand why she expects me to talk to her with respect when she treats me like a fucking child that has to respect her parent because she gave me life.

She also always says “don’t ever ask me for anything again!!!!!” As if she gives me sooo much 🤨 not.

What should/can I do? This is how she has always been and I have feared her my entire life. And please don’t tell me to talk to her about her actions, she will freak out and go on a rage.