"Pruning your peach tree in February would not have caused damage to the tree. That's the correct time to prune. And peach trees can withstand rather severe pruning with no ill effects.
There could be other factors involved in the poor growth of your tree. Late winter freezes (after the time of pruning) may have killed some of the buds; there may be borers attacking the main trunk; the main trunk may have been damaged from sunscald; or any of a number of other problems. Look closely at the main trunk or at ground level to see if you can observe anything out of the ordinary.
It's possible that the tree may yet sprout new growth."