I've have several serious relationships with friends and lovers who were bipolar. I don't ever get the real 'high' end of the upie/downie thingie. I'm just flat depressive, if I don't count my blessings and keep an attitude of gratitude. Straight self talk is what rights my ship.
My first impulse is to start in beating my self up emotionally and saying mean things to myself, that I believe the other person thinks. Helps to be self aware and see it coming and stop that shit before it starts.