No idea if this is in any way what you need right now. But i really love TheraminTrees videos about behavioral disorders like narcissism. Especially Part 1 and Part 2 about his experience with a cluster B (which narcissism falls into) parent.

This channel has given me many interesting insights into my life and the life of people around me.

Obligatory "dont take psychology advice from the internet at face value" and consider talking to a therapist if you feel like your relationship to your mother is significantly fucking up your current and/or future life.

You are not responsible for your parents happiness.

I lived this cycle for 7 years. Eventually I just stopped tiptoeing around the eggshells and did whatever the fuck I wanted then ignored her when she blew up. Then she tried to become an alcoholic and blame it on me. When that didnt work she finally found some other poor bastard work on.

I will be happily single for the rest of my life. Also fun fact: child support for two kids is cheaper than supporting her retail therapy habits.

My MIL is almost the same way with my wife and myself.

Stay strong. Hopefully you find a resolution sooner than later.