What should I do about my crush on him?

I’ve had a huge crush on this guy since last year. It’s the biggest crush I’ve ever had on someone that wasn’t a celebrity or something like that. We were in a class last year and he would do a lot of things that led me to believe that he liked me. He would always do things to look back at me and stuff like that. But he would never talk to me. Even if he needed some thing. Like one time he needed the notes and asked everyone around us except for me. He saw them sitting on my desk and I kept waiting for him to ask, but the went to the other side of the room to find someone else. His friends even the ones I didn’t know started acting weird whenever I was around. He’s a shy guy, but not like this. I’m also really shy. Especially around guys. I kept waiting for him to make a move, but he never did. So I basically have been trying to tell myself he never liked me because if he did then he would have made a move. This year I don’t have him in any of my classes. I guess that’s a good thing. I see him every once in a while in the hallway and sometimes I’ll catch him staring at me, but I just look away. Then on the 1st day of school this year this freshman walked into one of my classes and I was like wow. He looks like a little version of the guy I liked. A few days later I saw his ID card and found out he is the little brother of the guy I had a crush on. So now every day I see him and I think of my crush. He even acts weird around me. Like I always will catch him looking at me. He refuses to speak to me. Like if I’m standing in front of something he needs he will stand there and wait for me to notice him and move. Instead of asking me to move. He will talk to other girls. I also see him looking at me during lunch a lot and when I walk past his table his friends will hit him or something and he looks at me really fast. When I see him with his brother (my crush) they start whispering and stuff. I want to get over him and not waste my time on him, but I can’t. For some reason I can’t get him out of my head. I’ve never had a crush like this before. I’m worried that it will bother me years from now. 10 years from now I’ll be thinking about the guy I had a crush on, but he didn’t like me. I don’t want that to happen.