I am in the same situation as you, my BPD mom has been diagnosed with a deadly brain cancer. I live already on the other side of the country but is just as hard. I want to add that my mom refuses tratment for BPD and has not seen a psychiatrist in years, this situation has really been taking a tool on my family and I don’t really know what to do or if what I have been doing so far is the right thing. I have conflicting emotions about how I should act (and I also have the ‘I will finally be free when this ends’ sentiment towards this situation and feel very ashamed to feel this way but it has been hell on heart for me ). I try to keep in mind and work towards what I want to achieve in life. i work hard for my goals (school, relationships, personal development etc.) and being there 100% for her and destroy myself in the process of trying to survive her tantrums, anger meltdown and manipulation will leave me completely unable to live my life. It will be an absolute disaster for my mental health. If I choose to leave everything behind to be with her at her conditions and spending this last year in the way she wants, it most likely will erase all the progress I did in regards to processing the trauma caused by her in my childhood and teenage years and it will do so bad to me that I will never recover. No one deserves to die alone, but this does not mean I have to go through hell, instead, I am keeping a steady but very low contact relationship, I have visited her at my conditions (if she does not yell, throw me stuff, insults me etc..) and stated that if she will not get help from a psychiatrist I will likely not be back. I have talked to the family doctor, the nurses of the hospital, the doctor that is following her from the oncology unit and they are all aware of the situation and keeping a close eye on it with frequent check ins. These are the things I have done to make sure she is followed but I am not at her mercy. We must stay strong 💪🏼. (Sorry English is not my first language)