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.