Welcome kali3: I'm so sorry about the difficult time you are having with you mom. People who have normal parents aren't able to understand your situation, but you aren't alone here. Many here can relate to having BPD mothers or other family members and are willing to lend a listening ear, share and hopefully help you.
Does you mom live alone? If so, any chance to hire someone to help her with various things?
No boundaries again ... .
Boundaries are for you to set and enforce. They are for your protection. People with BPD (pwBPD) usually won't want to honor your boundaries. It is up to you to consistently enforce them.
Unfortunately, we can't change others, only the way we interact and react. The links below lead to some specific information that will likely be helpful. Working through FOG (fear, obligation and guilt), setting firm boundaries and employing some validation and communication skills can make things better for you. The information below can get you started with some basic tools.
FOG - DEALING WITH FEAR, OBLIGATION AND GUILTBOUNDARIES WORKSHOPCOMMUNICATIONS OVERIVEW VALIDATIONValidation (or minimally not being invalidating), can be a productive tool to use. It doesn't mean that you agree with your mom's position, just that you acknowledge her feelings.
AVOIDING CIRCULAR ARGUMENTSCheck out some of the tools/links and let us know what your think. Take it a step at a time, a tool at a time. I've found it helpful to bookmark some of the lessons as I discover them, that way it's easier to go back to them.
Some people like to read the articles/workshops and then come back and post to confirm their understanding and to practice ways to apply the tools to their situation. What boundaries would you like to enforce? What are some of your mom's most troubling behaviors?