Where are you? In the U.S. at least, chili powder is a not-very-spicy blend based on ancho chiles, but with other spices and often salt added. My understanding is that in Europe and Australia, it's just straight up chiles, so 3 tablespoons would be a LOT. Check out this thread -
http://forum.theppk.com/viewtopic.php?f=18&t=7382&hilit=chili+powder - for some past conversation on this and a recipe for chili powder. If you are using the right thing, then maybe what you've got is just really spicy?