I wouldn't answer her "I miss you" texts. Repeating it back is pursuing to a degree and it feeds her supply. She's trying to pull you back in toward her because something's going wrong with OM. Only once you're there, she'll push you back away.
There are many parallels in your sitch to mine. I believe she might severe emotional issues and you are co-dependent on her.
Stand on your own feet first. You can't resuce her, nor can you fix her. You can only fix you. Get to work...on you!
