It seems like she is trying to use you for her own emotional well being.
I would say that if there is any way possible it might be a good idea to live
apart as it sounds like she is going to be looking for ways to push your buttons
since the two of you have a history together. Sometimes it is tough to
acknowledge that someone is dragging you down and that you need to have
some time away from them.
Let her get the emotional support she craves from whatever guy she is
hooking up with as that is not your job. If she does not love you and
yet she cannot get that support from the other guy, well then too bad
Keep working on yourself in positive way and spend less time noticing or dealing
with her problems.