Greetings! This is a rather interesting question put forth before us, but there are a few key misconceptions within it that need to be corrected before we answer the more appropriate question: "Why did the Central Powers surrender when they did?". This response is going to deal first with the key misconceptions in the question first and then turn towards the aforementioned question. Let's begin.

Analysing the Question

The first part of the question which needs to be reframed is this statement here:

"But as soon as the Entente powers started winning the central powers surrendered so quickly."

Whilst it is true that the Entente Powers did win a series of critical battles in the late spring and summer of 1918, by no means did they lead to a rapid surrender of the Central Powers as a collective alliance. Each of the individual member states of the Central Powers signed their own armistice agreements, sued for peace, or sought separate agreements in 1918 which removed them from the war. We commonly associate the "fall" of the Central Powers with the November 11th Armistice which was signed by the German Empire, but we must not forget that there were other such ceasefires for the other Central Powers nations. Austria-Hungary signed the Armistice of Villa Gusti, which came into effect on the 4th of November, Bulgaria signed the Armistice of Salonica on the 30th of September, and the Ottoman Empire followed with the Armistice of Mudros on the 30th of October. Thus, although all of the Central Powers had ended their parts of the war with the Entente separately, it all occurred in the span of two months.

There is another problem with the phrase above as well. The "Entente powers started winning" statement is a tad vague, and suggests that there was a unified military offensive by the Entente on all fronts, as opposed to the reality of multiple offensives launched by the various front commanders and with different time frames. The German Army for example, faced the combined French, American, and British offensives from July 26th to the signing of the Armistice. Their Austro-Hungarian counterparts also fell to an Italian, French, and British offensive at Vittorio Veneto, whilst the Bulgarians on the so-called "Macedonian Front" sued for peace after their army collapsed in the Vardar Offensive, and the Ottomans were facing a hopeless situation after Bulgaria withdrew from the war. Granted, each of these offensives came within months (and in some cases mere weeks) of one another, but they were not the grand, concerted Entente effort that the question may lead one to believe.

The final misconception which the question presents is within this sentence:

"The central could have done some sort of massive counterattack against the entente powers since they annexed large portions of Russia but instead they surrender. So why did the central powers surrender so quickly when they just defeated Russia and got a bunch or [sic] territory."

The Central Powers (namely Germany and Austria-Hungary), had not "just defeated" Russia in the context of the timeframe. The Treaty of Brest-Litovsk had been signed (after much delay by the new Russian Soviet Republic) in March of 1918, and the Germans did indeed use the troops from the East to launch a massive attack in the West but more on that later. Secondly, although the large amounts of territory and resources that were gained by the Brest-Litovsk Treaty were substantial, they were by no means decisive***,*** and we shall explore this aspect further in the response next.

Surrender

The First World War had, by 1918, entered a critical state. On the Entente side, the entry of America into the war did mean a new source of troops, resources, and materials with which to continue the fight. However, those troops would take precious time to reach Europe, and there were not yet enough of them to give the Entente an overwhelming superiority in numbers. When America entered the war, its army consisted of just 6,000 officers commanding 100,000 men, and training the necessary reinforcements over in America would take time. The Allied staff officers had already begun planning for a massive offensive with an American army of one million in 1919, but it was doubtful whether the British and French could hold on that long. With Russia having been knocked out of the war in March, the Germans were free to move a significant number of troops (battle-hardened ones at that) from the Eastern Front to the Western front, and that is exactly what would happen.

However, if the situation seemed grim for the Entente, then it was verging on the desperate for the Central Powers. Within Germany, the economic situation was getting dire (but not, as postwar German propaganda portrayed it, to the point where a critical food and supply shortage was numbering Germany's days). The Reichstag (imperial parliament) had grown weary of the war, as had the general populace. Strikes in Kiel and Berlin, the mutiny of naval crews at Wilhelmshaven in August the previous year, and the declaration of martial law in Hamburg and Brandenburg meant that the home front was becoming an increasing concern for the military leadership of Paul von Hindenburg and Erich Ludendorff.

For Bulgaria the situation was even more dire, and the success of the Vardar Offensive (which saw Entente troops push the Bulgarians as far back as their capital of Sofia) resulted in the declaration of a Bulgarian Republic, which added to the growing problems of the government facing the war (the Republic forces would later be quelled after the Royalist government regained control). Thus the Bulgarians sued for peace, and the Armistice of Salonica was signed.

This Armistice brought serious consequences with it. Chiefly, the overland route between the Ottoman Empire and the other Central Powers (Austria-Hungary and Germany), no longer existed. Further, the Armistice allowed Entente troops to move through Bulgarian territory, which meant that they could now directly threaten the Ottoman capital of Constantinople (modern-day Istanbul). The Ottomans did not have the troops required to defeat such an advance, and the Middle East theater also saw losses for the Ottomans, with the British supported Arab rebels and General Allenby's Egyptian Expeditionary Force conquering Damascus and Aleppo. The Ottomans then sought peace, and signed the harsh Armistice of Mudros a month after their Bulgarian allies had fallen.

Next in line was Austria-Hungary. The Habsburg Monarchy was already straining under its internal ethnic conflicts, and Woodrow Wilson's Fourteen Points (delivered in a speech earlier that year) had stoked these conflicts/divisions further within the country. Their government had already attempted to negotiate a separate peace with the Entente, but the military collapse after the Battle of Vittorio Veneto was the final nail in the coffin of the empire, which soon broke-up into various new republics and countries.

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