Why do I get this feeling in my stomach after I talk to him?

I use to like this guy last year but i convinced myself that i didn't like him because i only thought he was cute and funny and i didn't want to like someone just because of my first impressions and i managed to erase my feelings for him in that way.

But now that i go to the same school as him and even though he's in a different grade, i talk to him more now. I like being friends with him but lately i get this feeling in my stomach as if I'm nervous about something! And i think it happens after every time i talk to him or think of him.

These nervous pains last for nearly all day if i can't manage to distract myself. I would imagine i would get use to these pains after a while but every time they hit it's like a new wound...

I'm getting tired of feeling this and I want to know WHY I FEEL THIS WAY!!!

Does it mean i like him?! But i don't want to like him because i know i'll just hurt myself for no reason!!!

Please lend me your wisdom and knowledge...