Hello, ARflowerstar. This caught my attention:
I experience short, sharp episodes when powerful contradictory emotions - rage and terror - overwhelm me, and I turn all of that against myself. During these episodes there's no possibility of me reasoning with myself. It's an explosion that ends with me on the floor exhausted in mind and body.

No doctor has offered a precise understanding of my episodes. I speculate you might gain insight into your situation if you could consult specialists outside of psychiatry - a neurologist and/or an endocrinologist possibly.

I'm sorry you've had such a rough time. Powerful emotions, both positive and negative, may interact.