I think it boils down to developing inner strength and toughness. For various reasons, I've always been a bit different, and in my senior year in high school, a very nice girl who was also very popular told me that I would never "fit in," but that was okay. I should not let people try to fit me into a box and should be proud of my accomplishments. I have remembered that and it was very liberating.
Bullies sense weakness. They only go after weak people. They are like predators. Predators in the wild only go after the old, the young, and the sick or lame.
I'll give you a couple of examples:
1. A long time ago, I used to go running in a park every day. There was a German Shepherd that would growl and menace me. So, I bought an expanding baton that fit in my pocket. The next day, I went running with my baton in my pocket and the German Shepherd took one look at me and then did not growl, but walked away! He sensed my inner confidence.
2. I've always been a good student, but math is my weakest subject. Calculus was my downfall. I took it again at a community college and struggled. I was asking a lot of questions and some guys in the back of the class would make fun of me. This went on for some time. So, one day, I literally stood up in class when they were snickering at me, turned around to face them, and chewed them out! I told them to STFU and they could meet after class if they wanted to confront me like real men instead of snicking like nasty little junior high school boys. Well, that shocked the crap out of them. The teacher just smiled and those guys never caused me problems again.
3. In nursing school, I was one of the older students. Two nasty little girls who were very young decided to make fun of me and roll their eyes constantly, because I was slow to learn certain manual skills. I complained to the professor, because I was partnered with them in lab and it was negatively impacting my learning. She switched me to another group and evidently gave them a hard talking-to. They would glare at me after that, but I just glared right back. I ended up making friends with very nice students that I am still friends with. I have no idea what happened to those 2 idiots, but I ended up on the Dean's List, National Honor Society, etc., and became an NP. Those 2 are probably scrubbing toilets or something.
In other words, don't play their game by their rules. You do your own thing by YOUR rules. It's actually quite entertaining to mind-f**k bullies. Be creative and have fun!
One of the best weapons is ridicule. I'm very good at making up hilarious nicknames that stick, because they fit well. Once that happens, people will be calling the bully that name behind their back. And every time you look at them, you know their secret nickname. It really takes people down a peg. Politicians do this to each other all the time. President Richard Nixon had the nickname "tricky Dicky," bestowed on him by a female congresswoman, and it stuck. Whether or not you like Trump, he is a master of this, and it drove his opponents nuts.
Look, those mean girls aren't going to beat you up or anything. And they can't negatively impact your grades unless you let them. Ignore them. Hang out with other students. If there are older students in your classes, make friends with them. Figure out who the best students are, then make friends with them.
I'm one of those straight A type students and am happy to help anyone who asks for it. Most good students are this way. There are plenty of nice students in college.