Do you have another tank in the house that's cycled? If so, steal some media out of the filter (if it's external, or able to be done), stick it in a stocking and pop it in the 2ft tank (even better in it's filter), nothing like kickstarting the bacteria colony with real live bacteria.
If you have a nitrite test kit test the water - are you getting high levels of nitrites as well?
Also, I would be doing the water changes every 2 days or so, possibly more than 25%, but not disturbing the gravel when doing them, important thing right now is to get the ammonia level down or the fish will keep dying whilst you wait for the bacteria levels to grow and deal with it naturally. So long as you don't disturb the gravel/decorations you shouldn't effect the bacteria colonies in the tank, but you can dilute the ammonia content a heap and make the fish more comfortable.