KIR,
I too feel your pain. This is hard stuff. Here on Sober Recovery we support each other, and understand.
If my xabf take a syringe of heroin and shoots it in his arm, he's gonna feel some pretty great relief. There's gonna be a time when there is no pain in the world, and everything is right. But, then it ends. Reality comes back, and the problems with it. Even worse, consequences of taking that hit come too.
This is how I feel about taking the "hit" of reconnecting with the toxic person in your life that when you were sane you knew wasn't really good for you. Yeah, you can call her. You can feel the incredible relief for awhile. But, you know it won't last. And then, when you come down from the high, things are worse.
Hang tough, you can do it.