If there's a baby boom, it's probably much smaller than OTL (war is shorter). On the other hand, there's much less population loss from the Eastern Front. So Germany probably ends up with population similar to in OTL, give or take, which isn't enough to populate the Lebensraum. The Holocaust presumably happens as in OTL (around 80-90% of Jews living in German-occupied Eastern Europe were killed, so in terms of area demographics OTL vs. 100% isn't too important). Does Generalplan Ost happen as intended? Possibly; Nazi atrocities against Poles and Russians were happening throughout the war in OTL, both when Germany was winning and when it was losing.
So Eastern Europe gets depopulated through genocide and doesn't really repopulate with Germans, despite increasingly desperate German measures to get Germans to move there, and then when they don't incentives for Dutch and Scandinavian immigrants to move there. The Dutch actually might, the German occupation there was pretty brutal, if not so brutal by Polish standards, but the Netherlands doesn't have the demographics to Germanize the area either. So it almost certainly ends up majority-Slavic, with something like the race relations of apartheid - German landowners, Slavic workers. Let's guess that the General Government area ends up 50/50 German/Polish, the Baltics end up 50/50 German/Baltic, and Ukraine, Belarus, and European Russia are maybe 90% Slavic, just with half of OTL's population.
German industry probably stagnates due to atrocious institutions - lots of court politics under Hitler and whoever succeeds him, even more brain drain than in OTL. There's a cold war between the US and Nazi Germany, where Nazi Germany starts out with lower population and resource endowment and better industry than OTL's USSR, but the trajectory ends up similar, with collapse within a few decades. The preeminent industrial powers are the US, the UK, and Japan. If the Pacific War happens as in OTL, the US focuses all its resources on it and manages to win ahead of schedule even without Russian entry into the war, but ultimately Japan gets occupied and transformed as in OTL, as a bulwark against fascism.