So I started a game as Fascist Romania and everything was going smooth.

Took Bulgaria and made it my puppet. Then I went to war with Yugoslavia. Germany helped out and I took the capitol, but when they capitulated Germany got most of it. (No big deal, planned to give to Italy)

Then Germany begins attacking Poland and the Axis is created. Hungary joins and then Germany gives me the choice, give up some land or war. Again, no big deal, just a tiny sliver of land.

During all this Russia has rebelled from the Soviet Union.

Moscow is in my sights

I independently start the war with Russia and my allies join.

We fought long and hard, two winters and we finally took Moscow. I looked forward to being able to carve up land and deal it out to my friends appropriately.

To my surprise when the Soviets capitulated, Germany got all of what was left, even though I did a majority of the fighting

All I wanna know is, why?

Tl;dr Germany used me like a dirty Slav