??????Am I in love???

There is a boy which I have exchanged only a few words with, but I think I'm falling in love with him. My heart was once broken so I don't want that to happen again. I don't want to lose my mind with this boy and then get my heart broken again. The thing is we were mountaineering once (organized by our school) and we were walking in a small group together and I got tired and stopped. Then he asked me what's wrong (that was the first and last time we talked), and I said I was tired and then continued walking. From that day we only say Hi when we see each other and that's all. But we study in the same school and we see every day... And I feel I'm falling in love with him. Is it possible to fall in love with somebody when you don't know him well enough, or am I just obsessed with him? Please tell me what to do??