I need help figuring this out? Please?

For the past three months (just a bit after school started) I begun talking to this older guy in my school (teacher, duh.) He's very nice, sweet, smart, independent.... unlike other guys (him being older is what makes him like that, I guess.) But the thing is that... every time I see him, my heart beat races and I just instantly go into my... sweet/shy mode. Is odd, no guy ha ever gotten that side of me out. And I'm scared of this. I don't know what it is. His smile is just so... CAPTIVATING. It really makes me flutter. He talks to me. He compliments me on what I wear. He calls me 'Sweet, smart, caring...' And, lately, I have been feeling like he has been trying to make up some more questions to keep me talking. Like last last time, I was with a group of my friends walking down the hallway when I saw his clroom. They all left to go into the restroom except for me. I walked in on him (it was lunch time and he was alone) and told him that he looked 'lonely.' He just shook his head and smiled as soon as he saw it was me. That smile, once again, turned that side of me on. We talked until my friends called me. They started walking away and well... He suddenly asked if I had to leave. I gave him a 'yes' and then a wave. What stopped me was that he said I looked 'good' with the pink scarf I had on and then try to look for something else to talk about. Am I wrong, or does he like me? I don't really know. I'm flustered by all this. I like him, I know that... Any advice on what to do? Please?