It's like they're two different people and one of them died

I'm way past wanting to be with her, but I miss the other one so much. As in, her other side, that would occasion appear. The thing is, my brain somehow required itself and it's like that nice, amazing person I loved is a completely different person to the vile and cruel one. I think it made it easier to not continue the cycle, not associating the good side with the cruel one. But the good one feels like she died, and occasionally I cry my eyes out missing her, as if she was really dead.

I don't know if this makes sense for anyone or if anyone can relate, but I'm having such a hard time. I want to talk to the nice side of her so much, but knowing she is "dead" and its impossible to do so is just so painful. And I'm also angry. I'm angry at the other side of her, as if she killed the person I loved so much. As if she killed the person I wanted to spend the rest of my life with.