Your mom is unstable and requires support, above and beyond what an adult child would be expected to give. Suicidal? It's likely she'll try again. She needs help. Putting her in a care home is likely the best option for her. If your town/city does not take care of their elderly well, consider finding her a place outside of your area so she will be well taken care of.

Two wrongs don't make a right. However, your own mental health counts, too. Having her live with you will not be a healthy choice for you. There's significant abandonment issues here.

This is a hugely important realization and one in which you'll need to break the cycle for. I'd strongly recommend you seek therapy to address this abandonment issues so you don't repeat this lifestyle with your own kids.

I understand your story. I believe my mother has NPD due to a life long list of behaviours that tore our family apart. I, too, have questioned who would look after her, later in life. She'll be 70, next year. I never had much of a relationship with her and have decided, in the past 5ish years to limit contact with her. I am her only child living in the same city. I do not wish to take care of her, nor would she want me to, either.

Ask your mom where she'd like to live. She may want to live in a care home, anyway.