Why does my mom down me and tell so many lies?

Does Mom suffer from Dementia?

I agree, you do not have to allow her to live with you. If she has money, place her in an Assisted living. Then you see her when u want. When she gets started you can leave. If no money, maybe you can find a nice Board and care that will take her SS. You do not pay for her care.

You just tell her "Mom this is not working".

In your last sentence you say that "If she wasn't here I wouldn't want her in my life at all" so get her out of your house ASAP. And why did you take her in to begin with?
No one deserves to be treated like crap in their own home, so start today looking into placing her in the appropriate facility, on her dime of course.
And if money is an issue she can apply for Medicaid. Your local Area on Aging Agency or Senior Services can help you get started.
You do have a choice and a say in this matter in case you've forgotten.

Move her out to AL, stop the bleeding she will not change. These living in the same house deals very seldom work out.

Your mother is a manipulator just as mine is, the only difference is I would never live in the same house as her, in fact I haven't spoken to her in 13 years. 13 years of pure bliss.

Start looking for a place for her, then you can become her daughter again not her caregiver roommate, visit her when you want to, if she starts leave.

Why live together?

Rivedale is right. Start looking for assisted living places near you. Talk with them, talk with social services, get a plan.. any other family members to help out? I doubt it... It's a big job and tag you're it.

Does she have a living trust? ARE YOU POA FOR HEALTH AND FINANCES?

Are you on her accounts? Joint accounts or POA?

Start getting that into place now...

Then you can enjoy her as MOM in her new room. She can talk and play games with other residents...
Then she gets to enjoy seeing you. And if she starts attacking you verbally, Oh Mom I am sorry,, I forgot, I need to go.. The kids have appointments tomorrow, and got to go and get ready for tomorrow.... BYE BYE... LOVE YOU! SEE YOU NEXT WEEK... :)

AND THEN AGAIN, YOU CAN CALL THE STAFF TO SEE HOW SHE IS.

Dear Whymewhyme
I am so sorry you are in this situation. At 90 there is probably plenty wrong with mom as she is very old. Just probably not anything that appeared treatable for her after examination in the hospital. I’m guessing here as you don’t give us any info on her health issues.
But I get it. She is living with you and you are worn down trying to care for her and put up with her personality.
Did you know it was okay to move her out? She might even be better off since she is so unhappy with you and your kids. I could not do what you are doing.
You need some space away from her. Big hugs and come here to vent. We care.

Because you let her. At this point, you have no one to blame but yourself. Cut her out of your life, permanently.

Does she have to continue to live with you? It certainly would be better for you and your children to not be continually around her. Don't know if you are able to consider having her placed in a facility. Lots of posts here over the last couple of days about this very subject. You wouldn't need to search far back to read them and get varying opinions regarding placement. Sorry you are having to deal with such negativity.