I can't figure out why my professor hates me I now have Professor X for the third semester in a row. I have not interacted with him very much outside of class, but I am positive he used to like me. But now, I can tell that he dislikes me.

I can only think of 1 or 2 reasons of why he would hate me (possibly valid, possibly not; for one, I complained about him to some classmates). But these reasons seem somewhat unlikely to be the cause. I have an (unfounded) fear that perhaps he mistook someone else's course evaluation last semester for mine (I did not actually complete one).

Is there anything I can do to alleviate the situation? I have considered asking him directly in person, but I think that he will either evade the question, or at best give one of the above-mentioned reasons; and if he does give one of the above-mentioned reasons, I wouldn't agree that they justify the professor being so upset.

I am emotionally disturbed by my professor's behavior. Additionally,  I will probably have to take him for two more semesters, so I would like to rebuild a decent relationship. I am at a very small school so at the same time I fear that this professor might talk negatively about me to his colleagues. 

Do you have any advice on how I could improve the situation?
My answer to your question is, I believe, pretty good advice to follow in general: you should act professionally.

At the end of the day it doesn't matter whether or not your professor likes or dislikes you. If you handle yourself professionally (show up to class on time and prepared, complete your homework assignments to the best of your ability, ask for help when it is needed and interact respectfully with your professors) then you should expect that you will be treated fairly and equitably and should complain if you aren't. 

(I've taught at the college level for more than ten years and have never disliked a student. The worst that happens is that occasionally I'll have a student that I find exasperating -- perhaps they talk over other students in class or consistently show up to class 5-10 minutes late -- but these sort of students pop up so regularly that I can't imagine actively disliking any of them. I have a similarly difficult time imagining a professor actively disliking one of their students barring some sort of (extraordinarily rare) extenuating circumstances.)