After what is left of Russia and Germany reach peace I would focus on going after the UK's colonial holdings. I would get the Spanish into the war one way or the other and take the Gibraltar. I would focus the German, Italian, etc war production on defeating the British in the Mediterranean.
I think those were tried OTL, and none of them worked.
I suspect the British on their own won't last that long before they get exausted and kick out Churchill and make peace. Then I fulfill my end of the deal and end the occupations of European countries after elections are held. Oh, and I set up a European NATO of sorts so if Russia attacks Ukraine that Germany and other European countries are obliged by treaty to respond.
If you're focussing on the Med then you're pulling all your U-boats from the Atlantic (U-boats were about the only extra resources could give to the Med, every thing else requires shipping, which gets screwed up at the insufficient Italian ports), which makes life easier for Britain, not harder.
Basically the only card Hitler can (or at least
will, without an ideology transplant) play any better than he really did OTL is putting Speer in as minister of armaments and war production.
As for the rest of it, Greece will have to go eventually, even Crete, British bombers based out of there could have hit the Romanian oil-fields, and air-defences pull resources away from Barbarossa. Ending the Atlantic war is a no-go, with Sealion off the maps, starvation is the only way to reduce Britain. Making promises is not going to assuage resistance, Hitler had already broken too many for anyone to trust him. You might get more success with integrating former Soviet forces, but again, that will require an ideological implant, and it still won't give the Germans victory in Russia, it will just slow the Soviet counter-attack.