10 bucks says you're ammonia's spiked because you didn't cycle the tank. You are now doing a fish-in cycle (don't worry, I've been there done that too!). Go get test kits (drops and test tube, not sticks) for Ammonia, Nitrite, and Nitrate. Start daily water changes. Do not vacuum the gravel, because you need bacteria to start culturing so that it can stabilize your tank. And read all the stickys on Cycling a tank. You won't find much on a fish-in cycle, but at least you'll know what your fish are going through right now and what to expect. Oh, and you really only need to feed your fish a few flakes 2-3 times a week as a general rule of thumb- but especially since you're probably experiencing ammonia spikes. Keep us posted.