Sorry you are going through this. I know how difficult it is to keep swinging around. It might be the bipolar trying to stabilise or something else. I have PTSD and that can make my moods swing badly at times. It helps to try to stay grounded with mindfulnes, meditation or grounding techniques. Do you have a therapist? they can help with things like that. Also your meds might need tweeking, if you are on any.