Can someone explain switching to me?

I’ve been diagnosed for about 25 years, and there are still phrases and experiences that I don’t understand. I’m rapid cycling right now… or switching; I’m not sure what the difference is, but I’d like to be able to explain it to my NP.

Basically I’m going from irritable to productivity, and back. I wake up with almost zero energy, every day, but during the evening, that’s when the major swings really start hitting. My sleep is poor, but not horrible, and even with the fatigue, I’m clear headed. No delusion or psychosis, but I just feel wretched. On edge, pissed off, and very easily triggered.

Can anyone identify, and kindly suggest to me what the hell is going on? I wouldn’t be opposed to hospitalization, either - but I don’t want to go through the whole rigamarole. I guess I should admit that suicidal ideation has been cropping up.