On and off flatline/libido

Heya, I'm currently on day 47, and recently I've been feeling quite depressed. Some days I feel like I don't want to do anything. I feel irritable, then angry, then sad, for no reason. I've read up on the flatline multiple times, and assumed that I've probably reached this stage of the NF journey.

However, a few days later (now), I feel aroused as hell. Random boners, dirty thoughts (which are way harder to suppress than usual), attraction to women. All stuff that shouldn't be happening in a flatline (at least according to what I've read)? Still feel a lot less energetic than I was.

Is this how flatlines are supposed to/can be? For the past few days, I really felt like shit, and now I feel like I could bang anything that moves. Anyone else experience anything like this?