After being told that his legs didn’t have to be amputated, R’ Leibke Glauberman replied, “I heard from my rebbe, the Yanuka (R’ Yisrael of Stolin): to say ‘if only I would have done things differently…’ is apikorsis. 

Everything is destined from Heaven.  The doctors may say that an illness such as I had didn’t call for amputation. But my legs needed to be amputated nonetheless, because that was decreed from Above.  It wouldn’t have happened if it wasn’t Hashem’s will.