@Robert59 - Has your girlfriend seen her doctor recently? You mentioned that she has bipolar disease. Sometimes changes in behavior could be a reaction to a medication. Or medication doses are missed or taken too frequently. Can she see her doctor with you so you can explain what you have experienced? If you feel her doctor is not responsive to any concerns, maybe it is time for a second opinion.
I really feel bad for all you are going through. This is not easy at all. Has she appointed a Health Care Proxy? That would take effect if she could no longer make her own decisions for her health care.