Welcome Lulu,
Sorry to hear about your Mom. But don't give up hope!
Your moms psych. problems reminds me of my MIL. She had a lot of problems, had depressions and attempted suicide. Then she got coloncancer. To our surprise, she handled it very well! She was strong and wasn't depressive at all at that time! Unfortunately, the mental problems came back after the treatment for the coloncancer stopped.
I don't know about your mom, but there is a possibility that she is stronger than you think!
Ellen.