I've been mother's live in caregiver for over 5 years. She has become delusional and has called the police 5 times wanting me out. Advice?

You call an ambulance the next time she lashes out. She gets taken to ER. You tell the ER she cannot return home as you are afraid she will continue to attempt to injure you. Tell them that she needs to be fully assessed. You contact the social worker at once to tell them she cannot return home, and needs full assessment. They will also be able to help you get guardianship if she proves to suffer from dementia. They can often get temporary conservatorship for you with a call to a judge whereas otherwise it can be difficult and costly through a lawyer and court system.
You do not say if you live with HER in HER home. If that is the case all of this becomes a good deal more problematic. If she is considered competent and returned to her home you will need to leave, yourself. You can then report her to APS as an elder at risk, in need of their case care and assessment, and you will need to get on with your own life.
If all this came on suddenly she may have a UTI but it does sound as though you are describing something a good deal more serious.
Either your Mom is competent or she is not. Assessment in hospital is the only way to ascertain that. So next outburst call 911. When ambulance attendants come she will likely fly into a rage. That will be a good thing, and will get her taken to the ER. From there, she is either sent home as competent or she is assessed. If she is competent there is no way to force care on her for either her aneurysm or her breast care. The former is likely untreatable; the latter is treatable but no one can force her to treat it unless she is completely incompetent to make her own decisions.
Wishing you luck, and so sorry you are going through all of this.

You Mom needs more help than you can give. There are meds to help the paranoia but since she won't go to the doctor nothing u can do there. A POA is out of the question since she is incompetent. Guardianship would be what you need and it can be expensive. Medicaid does allow you to use her money. I would call Adult Protection Services and run this by them. See what suggestions they can make. Office of the aging too.

I am so sorry that you have endured this pain and suffering.

How long do you feel that you can continue doing this? You’re going to hit a breaking point if you don’t choose to stop it.

Look at it this way. You have done all that you can possibly do to help. Has it helped? Be honest. No, it hasn’t.

Your mom needs more than your good intentions. She needs the best possible care which is to be in a place that is safe for her, and equally as important is for you to be safe, both physically and mentally.

Contact a social worker. Contact a therapist to help sort out your emotions.
Start looking at facilities.

When all is settled you will feel better knowing that you did what was best.

Take care.