It's possible that you cycle very, very rapidly. It's more common than most psychiatrists will admit. I've cycled within hours, several times before. I also have lengthier periods of mostly higher or lower mood, but it is never constant. There are always fluctuations.

Getting rid of all the serious depression made a big difference for me. Now I cycle between being elated, irritable, "normal", and occasional depression. Since the depression is rare, I don't mind the rest of the cycling. It can be uncomfortable at times, but it is better than being constantly depressed.

If you could nearly eliminate the mood that causes you the most trouble, you might find that you can tolerate any remaining cycling.