Whether she has DID or not, she sounds like a toxic person to be around. You say she's addicted to meth, and you say you have a daughter. How old is your daughter? Does she live with you? Is she old enough to cope with you being in a relationship with a drug addict?

It could be that your girlfriend isn't really someone you should have in your life, both for your sake, and your daughter's sake. Sorry if I sound heartless, but we're both Moms, so I feel for you in this situation. If you have issues of your own, and she's messed with your head to the point where you've needed counselling, then you need to look after yourself. I'm sorry you've had all this rubbish to wade through.

And amandalouise gives excellent advice... if your partner really thinks she has alters (and isn't just putting it on) then she really should see a pdoc about it. she should see a pdoc anyway about the drug abuse, if nothing else.