How to have a relationship with someone who is severely schizophrenic?

My mother and I’s relationship is odd.

I’m 30, my mother is 51. Since she was pregnant with me/shortly after at some point she was diagnosed with severe schizophrenia. She did not take medication while pregnant with me. When I was born, she was in and out of psychiatric hospitals for months while my father mainly cared for me until she came home to attempt and care for me, which was poor at best.

My parents divorced when I was a few years old. I would see my mom on the weekends until I was about 12, we moved away, and we stopped calling her, contacting her… my dad isolated me from all family.

Fast forward to about 3 years ago, I moved back home to where my mother is and started contacting her again. So I went from age 12-27 without ever speaking to or seeing my mother. As far as I knew, she didn’t even bother to reach out, or know what happened to me/where I was.

She is still severely schizophrenic, and from what I’ve been told by other family members no medication really works for her well enough or long enough. She has never been ‘stable’. She has never had a job. The state gives her money for rent etc. she has no car.

I’ve found it very hard to deal with her at times, and she seems to do nothing but bring hurt to me and my 10 year old sons lives…

She will be nice over the phone for a while and then snap one day. Call me repeatedly, ask me about things that never happened, call me names etc

She keeps saying she wants to see me, but she has no car, and makes no attempts to ever find a way to my house, which is 45 mins each way. So I plan with her week after week to go pick her up, bring her to my house, make her dinner, hang out with my bf and son, but she cancels. Last night she said I think a storm is coming? I don’t want to go out in that! There’s literally a 30% chance of rain tomorrow…

I’m not sure what meds she takes, and she will not even openly talk to me at all about having schizophrenia, she may have paranoid schizophrenia from what it sounds like to me.

Anyway, she is really disappointing and exhausting. It’s like I have an adult child. She calls me every few days, I can’t really ignore her. But I also feel bad for her… it’s an exhausting relationship. I don’t have a mom I can ever do normal things with. My dad was abusive and died a few years ago. I’m just unsure how to deal with her.