Glad you are looking for insights here at Psych Central. Too bad your girlfriend is resisting meds. They could stabilize moods or reduce down swings.
If she is not open to meds, what about a therapist or couples counselor? Some people at PC will find a therapist will help them sort out the roots of their life.
Some people find the forums give them the compassion and empathy they seek.
http://forums.psychcentral.com
There are articles that go into more detail about coping
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