sclc stage 4 - personality changes

Hello all, I know there are multiple topics on personality changes during and after chemo and radiation. I know about chemo brain and roid rage. My mother, (age 55), just finished her second line treatment of chemo, however she has made it to the two year mark and, luckily, for being diagnosed with sclc hers are being quite cooperative with treatment (knock on wood). She definitely has chemo brain with the memory problems and foginess. However, she is not on steroids. She has a history of anxiety, depression and insomnia and has been on benzos for years. Since her diagnosis, she’s had an increased difficulty in sleeping and since her tolerance for sleep and anti anxiety medication is so high, it doesn’t seem to work for her anymore. 

All of this has accumulated into a very angry, unfiltered, hurtful person. Completely opposite of what she used to be, which I have also read is normal. But she also seems to have an increase in paranoia, and her sense of reality has changed. Like, almost a mild case of psychosis. What she sees and process are not actual reality. 

So my question is: at what point is chemo brain/rage and personality changes normal? And at what point does it become that the issue could not be so much the treatment being the cause, but an actual mental illness, since my mom has had a history of mental illness. I haven’t heard of chemo causing psychosis and paranoia, is this normal? It also makes her very hard to have a conversation with. Trying to reason with her or tell her that certain things she says or do are incredibly hurtful gets flipped into you don’t understamd what I'm going through, I am sick so therefore I can treat everyone around me incredibly rudely. And also gets flipped into your yelling at me or your angry at me or your just after my money and don’t love me. I can’t descern what is, on average, a ”normal” reaction with being diagnosed with cancer, and how much to just let go because she’s sick and how much is actually wrong no matter how sick you are. 

Also, for most of my life, I’ve been told by my family and my own mother that she wants to die. She’s not afraid of her death and would prefer to go on her own terms. She has attempted suicide on several occasions many years ago. However, now that she’s being faced with the fact that treatment is never going to end until it is no longer effective, she still says she wants die. But, her actions says that she actually doesn’t want to die and fears death, by continuing the treatment even though it makes her miserable, even though she repeatedly denies this. She still continues to smoke cigarettes. So is she willing to accept death or not, does she want to die or not? She refuses to see a counselor despite my constantly pestering her. As someone who also inherited this depression/suicidal tendency I’m having a hard time wrapping my head around it, and if anyone has insight for this it‘d be grearly appreciated.

And how do I balance treating her like a child and still allowing to feel that she has autonomy over her life. Some friends are just like just treat her like a toddler, if she doesn’t want to do something force her to do it, scold her, etc. but on the other hand, she a grown woman, and I’m sure being treated like that makes her angry and uncomfortable and feel like she has absolutely no control over her life anymore.

Lastly, my mother and I have never had the closest relationship. We’ve rarely been together since I was adopted by my grandparents at a young age. I definitely love her, because of the bond between mother and child, but I don’t understand what kind of person she is. And only in the past few years have I come to realize she’s not who I thought she was. And now with the cancer, and her being so toxic all the time, sometimes my love for her gets taken over by resentment  and borderline hate. How can I deal with these feelings? Is it normal to have such a reaction to someone who gave birth to me, or am I just thinking selfishly and need to grow up?

Please, if anyone has any insight or experiences similar to mine, I’d be happy to hear them. Sorry this post was so long.