Why do I act this around him???

I'm 16, and in about 5 months I'm going to sit exams that literally determine if I go to college, university and pursue a professional job. I really want to focus, but there's this one dude that I act so weirdly around. I don't talk to him or anything, I don't even have him on social media. I have some classes with him, and I just feel so on-edge. Like I literally forgot the directions of left and right, And Just more clumsy when I try to at normal. I don't know hat this is, but I hate it. I don't want this at all.

He is kind of good looking. His eyes make me feel like he's staring into my soul. WHAT DO I DO?