How do I get my Mother to leave my home?

I assume you've already tried reasoning with her about moving out of your home and have tried finding her suitable low-income housing that can meet her needs. Often times this can be futile because there is a very long waiting list on housing and from what you're saying she refuses any other living situation that isn't in your home.
The next step is to call 911 the next time her terrible behavior starts up. Tell them that you need an ambulance because she is mentally ill and that you fear being harmed by her and that you fear she will harm herself.
They will take her to the hospital and likely keep her there for a 72 hour psychiatric evaluation. She will also get a physical assessment. During that time a social worker from the hospital will contact you to talk because your mother has been living at your house. You must tell them that you never agreed to be her caregiver and refuse to do it because you are unable to. Tell them that she came for a visit in March and has been squatting at your house ever since because she refuses to leave.
Because of her age 66 and also going blind and deaf they will likely place her in a nursing home because of these conditions. They will put her in one for mental illness too if she is a non-functioning adult at risk. This is the best possible outcome
depending on nursing home availability and what the mental/physical assessment in the hospital determines. They may also transport her to a homeless shelter if they're unable to find her a bed right away in a nursing home facility.

Aside from the good guidance already give you about protecting yourself. You state "she has undiagnosed mental issues and refuses to get help" -- you're posting on an age-related forum but I must comment that 66 is quite young for age-related decline. Are you saying she has mental health issues that are not related to her age? It is possible that an untreated UTI can cause some very bizarre behavior as a symptom in older woman. Again, your mom is not that old. Any other information about your situation would be helpful. I wish you much success in improving your situation.

Call the police the next she is abusive. Tell them she has mental health problems but refuses diagnosis. If you’re lucky that will set her off and they will take her to ER for evaluation. Do not take her home. Do not allow her to use your address for mail.

Or set a date for her to be out. Put it in writing. If she does not leave, go to the sheriff’s office and have her evicted. You do not have to keep her. Let the state be her guardian. They will find her care.

You have taken her into your home. As to how to get her out now I consider that a problem that is more or less difficult dependent on her ability to function for herself in getting a place to live and paying for it, and according to the laws of your state regarding tenancy. Some locales will consider her to be a tenant even if she is not even paying. You describe her as not diagnosed, and as having some problems with hearing and eyesight. You may want to contact your area Council on Aging or Adult Protective Agency and tell them where you stand on all this. If she is unable to function on her own she may require guardianship of the state, and I mean function financially, physically and mentally.
The fact you have already made the poor choice to take her in makes all this very problematic indeed. I honestly am at a loss to tell you where to begin and I hope that others will have better ideas for you. You are likely aware of your Mom's income. Were you to find a place nearby, studio or room rental would she go to it.
Ultimately, as to the abuse she is now physically leveling on you I think that may be actually the only GOOD thing you can use. Call the police and see about getting her removed to hospital, shelter or wherever and tell them you are in fear for your life. They may call EMS and have her transported to ER. Once there refuse to take her back in.
I hope others have better advice for you than I am able to give you. This will be a really serious problem for you and a serious warning to others thinking they can care for a mentally ill senior in their home. Wish you the best of luck and hope you'll update us as to what works.