Whenever I tried to make sense of the reason behind his actions I seemed to look pass the fact that it was me who first created this dynamic (one day I would be smiling and waving and cheerful around him and the next I would ignore him or not look him in the eye).

This definitely has crossed my mind, and I think I'm going to try what you suggest and be normal to him for a while, to the extent that that's possible. Like even if he's being cool I'll try to be normally nice.

What's funny, though, is long before I had even an inkling of a crush on him, there were a few times where he'd be kind of cold towards me, despite being usually a very sweet person, and I remember it because I mentioned it to my husband, confused about why this work superior was acting this way. But now that I'm doing it back to him sometimes, I'm probably making it worse. I think part of the reason I do it, aside from simple awkwardness, is the fear that if I'm too nice to him, he'll figure out that I have a crush on him. The rational part of my brain knows that's ridiculous. In truth, realistically the only actual evidence I've shown him to let on that I have feelings is my hot/cold behavior.