You allowed yourself to fall for a person who you knew to be unstable. Now you are seeing the results. This will likely never change. She needs to be the responsible one and step up by taking her medication. This will not happen with you in her life as being the enabler.
Chase her??? I find that a question incongruent with what you know and have experienced with her. Personally, I do not chase anybody. They are either there or not. If they have real issues with being there for me, I move on. Perhaps you can learn from this example.
I do wish you good in whatever you choose to do.
Tucson