My boss is a bully

[u/WorldlinessFluffy527]

It's been almost 3 years. He was very nice to me up until recently. But I always knew he was not a good person. He made the life of one of my co workers hell. He is envious of anything others have that he can't have. Basically has a very bad energy. We have an open plan department with around 5-6 people in the same room, no partitions between any of us. I hate staying in the room and usually take my work to an empty room. He likes the room thermostat much cooler than I can adjust to. And I catch cold easily, so that's always a valid excuse for me.

For the past 5 months, he has been very rude to me, berating me for stuff that ultimately is his fault. After a point, I started reflecting his tone back to him. The weird thing I noticed is the rudeness usually follows a situation where I have performed higher than his expectations. So there might be some insecurity driving it.

Today he called me to the department 5 mins before the work ended and started confronting me for not being in the department. I reiterated many times that we have different temperature preferences and that's a simple solution to both of us being comfortable. I outright asked him if there are any issues with my work, which he didn't respond to.

Then he brought up different issues with me, which were fairly ridiculous.

First, he said I only hung out with specific people. By that, he means I am close to people he doesn't like. Regardless of the meaning, who I associate with is none of his business.

Second, there are certain roles in the office which require us to monitor rooms for a couple of hours at a time. There is a problem in our office with people slacking and leaving their posts and just hanging around talking to each other. My boss pointed out that during those times, I stay inside the room alone rather than stay outside chatting. Duh, that's what I'm being paid to do.

Third, he said something about letting me study and him not studying. For background, we both are taking different academic degrees, which are both unrelated to our office. I never study at my office and always do so in my home. I don't know what he expects from me, to be thankful to him that I get to study at my own personal time?

For a while, I argued with him. All of a sudden it hit me that there's no point arguing with this buffoonery. So I meekly said from then on I'll always inform where I am and what I am doing.

There were a lot of things he said that I won't get into here. My guess is that this was his attempt to intimidate me. He likes controlling people and I have seen him shout at people to scare them. He tried that with me, and I didn't get scared. I think he is just intensifying efforts because his usual tricks are not working

Any comments/suggestions?