What problems in Germany helped lead the German government to appeal for an armistice?

This questions refers to World War I. Germany had many problems in 1918. While the nation had a U-boat blockade of Britain, it was really the British blockade of Germany which hurt the economy more and killed thousands due to starvation. Britain mined the North Sea, essentially making Germany landlocked by 1918. The nation was also hit with fertilizer shortages due to a lack of nitrates; most of the nitrates went for munitions. A couple of years of bad harvests and the winter of 1917–18 was quite brutal—it was referred to as the "Turnip Winter" as the German people were forced to eat food they would normally feed their livestock.
Militarily, Germany was struggling. The late-summer and fall Meuse-Argonne offensive took place after the German all-or-nothing gamble to take Paris that summer. The German soldiers, told that their enemies were suffering, felt betrayed that summer when he reached Allied trenches and found them well-stocked with food and supplies. The surge of fresh American troops led to Germany losing territory all across the Western Front in the fall of 1918.
Germany also had governmental problems. Ludendorff had essentially taken over the government and had gotten rid of many liberal reforms, most importantly criticism of the war effort. By 1918 Kaiser Wilhelm II was largely a figurehead in his own government. The collapse of Russia meant that many German prisoners of war were coming home, some of whom had been influenced by Bolshevik propaganda. Germany signing an armistice in 1918 was done largely to prevent a Bolshevik uprising in Berlin. Hitler's government partially blamed the Communists for selling out the German people in World War I; this partially explained his aversion for the Soviet Union.