What should I do??

It's been awhile since I've liked this guy.And when I'm doing my duty he would always go and talk to the seniors that are around me.Is he doing that on purpose?But there's this guy that I've liked since primary school.He says that he likes me too but everytime I see him with another girl.It's as if he's playing a trick on me.I can't take it anymore.He asks me whether did we start and I said maybe,I don't know but to him we never started at all.I think he's playing a trick on me.If he is,then I don't want anything to do with him anymore.It would seem that some of my friends are also facing the same problem as me.Should I ignore this feeling and just study hard in order to pass my exam?Or should I face the truth and tell this guy how I truly feel about him?But the thing is one of my other friend also ike this guy.Should I back out and let her have him?Or should I let the guy decide who he wants to be with?So many questions and so little time to answer this questions.I keep feeling that I don't have much time left.I feel as if I have a disease.Is it really true?If it is,then I wouldn't want to make the people that I care around me to find out.It might change their lives forever.So if I'm really diagnosed with a disease,I should keep it to myself.That way,no one would find out and I don't have to feel as if I'm being sympatized and I don't have to feel bad about it either.This can go on forever.I don't want to fight with my friend over a guy but I can tell,she really likes this guy.