"I think that our relationship is very unhealthy and I kinda want her out of my life."....Uh...you think?
You sound like a reasonable person. She sounds like a rather unstable individual (and I'm being kind). You are waaaayyyy too nice. Do you have a problem saying No to people? That may be your weakness. Even people that abuse you? Perhaps it's something you need to be aware of and work on.
You owe this woman nothing at all. There are no bridges, they are all burned down. She is using your place as a crash pad. Are you Motel 6? If not, then tell her NO. Practice it with me..say it over and over until you get her on the phone...NO...No....Nooooooo.... and HELL no. I'm sure you'll do it in a graceful manner.
And BTW, if I was much younger, I'd find you and date you myself, and I wouldn't care what you had on your nether regions.