How often should adult children visit elderly parents?

I have severe social anxiety disorder and it took me a good 20 years to forgive my mother for enabling my abuse as a child, and her continued choice in mate causes me a lot of issues. I’m fairly happy that I live over 500 miles away and am way too poor to ever visit. Even from such a distance she’s managed to cause problems in my marriage and general well-being.

My younger siblings have a much closer relationship with her, probably because they never had to know their father, and never had to suffer through being her first born son.

All my aunts and uncles who seem to have any degree of happiness were ones who moved far away from their parents (my mother’s mother in particular). Yet my grandmother now lives with one of my uncles at the end of her life. I could never do that.

There is no Should.

YMMV, a lot.