People who make me feel like crap or worse off then when I encountered them consistently are written off and out of my life
Doesn’t matter if its family, nobody is entitled to your attention and suffering and it does nobody any real good for you to succumb to the inevitable dysfunction it creates in your life and relationships and also material conditions.
The way that someone responds to you is a reflection of them, not of you. If someone in your life is wildly inconsistent, all you can do is make sure that you are maintaining consistency yourself.
I’ve worked with a number of people who acted like we were besties one day and then gave me the cold shoulder for weeks. I spent too many years wondering what was wrong with me before I finally figured out that their mood swings had nothing to do with me.