Crashing Walls

What does it take to really know how someone feels? I don't wanna to say I've fallen for someone but I can say I got it bad. Something I really wish doesn't really happen to me. I'm not suppose to like anyone for the fact I look and read into every little detail. That shouldn't really be happening to anyone actually. Beacause ths moment you let your gaurd down that's it. Everything goes downhill from there. Only the lucky ones don't get that downfall. I know this has happened to me all before and i know it's going to happen again. But for some reason I try every possible reason to not let someone get to me. How does one day affect everything that you've worked hard for? I've faught every other person who tried to get through me but this one, so effortless, he got through. Now everything has come down with one visit, one hug, one smile. . . It just doesn't seem fair. I'm terrified and can't keep it together...