How can i become less self conscious and accept myself for who i am?

Heey, so recently I have been looking in the mirror, and wish I hadn't. Thinking to myself that I am hideous, and not a worthy person. I used to look at myself and think, I'm definitely not ugly but i am not beautiful either, just average. But, these days my thoughts drift to my negatives. It's not even just my appearance, it's my whole personality. I'm continuously worried that the girls are judging me, and laughing as a walk by them. Even people I have never talked to before. I am a freshman this year, so I've had girls yell things out at me a few times and then laugh. I have been told by a few guys that I am attractive, and especially this one who is a year older than I. He will randomly just say i am beautiful. I used to accept it, but now i think he's just mocking me, laughing at me behind my back then telling his friends about how I responded to his compliment. Today, I knew I had to write this out. I was bummed out for the rest of the day when i walked past a group of people they yelled out babe. I slightly turned my head, then i heard them say not you, ewww. Then laughter. I am not positive, but my mind has made it up in its head, I swear I heard it. It really hurts to hear things like this even if it may have not even occurred. Any suggestions to how i can? Today, after returning to cl from the group that yelled out to me, I wanted to go home and skip the rest of my cles. I don't think it's healthy for me to evaluate, and worry about what others think of me anymore.