I think you are underestimating just how dire the situation was in Germany. The country's rations were so low that people were starving to death en masse in the cities. They couldn't pacify the east post Brest-Litovsk, and starving the Ukrainians did virtually nothing to ameliorate the famine at home.
They could and did pacify the East to the point they could transfer (IIRC) something in the order of 38 divisions to the West for Operation Michael. Upon the Wars end, the blockade would be lifted, supplies could be brought in. Maybe even food shipments from the Allies instead of cash reparations?
Even without direct American involvement the blockade was crippling Germany, and the unproductive agricultural sector couldn't cope with the mass mobilization of men for military service.
The blockade would end with the end of the War. The real, crippling damage to Germany was done in the last Winter of the War and 1919 when the Allies kept the blockade in place, that wouldn't be the case ITL.
Getting a white peace would make things scarcely better even if they secured it promptly. Even worse for the establishment, they won't have any November traitors or foreign enemies to blame for the dire economic straits they're in.
A White Peace is the whole point of this TL and it would make all the difference. Who needs November Traitors to blame
when you've won? You blame your enemies, who you've defeated. It's obvious that the 'dire economic straits' are the fault of the British blockade and the French. Remember, in this TL there are no reparations for Germany to pay, all that post-War economic recovery can go straight to making life better in Germany.
They can't afford to fight any longer in the East. They'll have to demobilize and put men back in agriculture or millions will die.
They don't need to fight any longer in the East, they've won. They can keep a smaller Army of Occupation in place - Weimar Germany managed 100,000 men, all the various Freikorps and the Baltische Landwehr (which together is probably another 100,000 at least) without too many problems. A victorious Germany could demobilise the majority of its armed forces for return to agriculture or industry and still maintain a large military. Times would be rough, for sure, but they'd get better soon enough.