Question

how hitler lossed his power

Answer 1

Hitler was in war against the Russian and towards the end of the war his army (the Nazis) were being outnumbered 15 to 1 and Adolf began being paranoid about the Russians capturing him and torturing him because of the many horrific things that he did to the Russians soldiers and this led to him plotting his own death and this meant that he was no longer in power because his army was slowly disintegrating. Later on April 30 1945 Hitler was so worried about the Russians that he eventually shot himself in the head with a pistol and the rest of the Nazi soldiers that were still alive did not know about this until the German soldiers had to surrender and they had no one to lead them after that, so this lead to the soldiers realizing that he had killed himself in his safety bunker.   

Answer 2

Invading Russia might be Hitler's biggest mistake but there are other important miscalculations. Some are possibly more egregious than Operation Barbarossa.
He declared war on the United States, the single greatest industrial power in the world. The decision borders on the stupid. One historian says Hitler made this decision in a moment of absent mindedness. It is ironic that Churchill's greatest Christmas present came from Hitler. Churchill said once the US was on board he knew Hitler was finished. Germany declares war on the United States — History.com This Day in History — 12/11/1941 The entire population of the United States, under threat from the Japanese as well, became single minded in their pursuit of victory over both aggressors. For the first time ever women entered the workforce in huge numbers and proved once and for all they could do a man's work and do it well.