I have a similar situation. My mood goes up and down like roller coaster, sometimes day to day.
I asked my Pdoc about it, and it wasn't rapid cycling necessarily, but he said it's a "mixed episode". I guess mixed means that you can be up and then down, or a mixture of up and down.
My main symptoms of my mixed episode was irritability, which is the whole reason I got a doctor in the first place.

Lamictal is starting to even out my moods a little, but I think I might need a higher dose.

Glad to hear your mood has stabilized.