I would offer the USSR everything save Germany itself for a peace.
Stalin's a pretty cautious guy, so I think it would be quite possible that he would agree, just so that he can make sure all of Eastern Europe is firmly under his control before eventually betraying Germany.
In the meantime, move troops west and fortify France further. This will, hopefully, force the W. allies to rethink their plans for opening a European front. With luck, Germany gets, perhaps, a year of down time.
Using that, I can get my shit together and establish a strong defensive line in the east (rather than overstretched OTL 1944, which allowed the Soviet offensive to annihilate the Germans) and start re-strengthening our airforce like crazy. When the Soviets come, bleed them out on the Oder and then hold them on the Rhine. If late D-day happens, crush them on the beeches with strong reserves.
Everything will then ride on our air defense capabilities. When the USA gets the bomb, we need to be able to protect the heartland of Germany from air bombing, or at least keep it risky for bombers. If this is achieved, then I will keep some bargaining power.
I will offer to free France, Yugoslavia, Denmark, Norway and Greece. Surrender Italy and her holdings over to the USA/UK and officially take blame for the war. Also promise reparations, and limit the size of the German army if I have too, but not to the degree of Versailles. The Soviets will probably be freaked out by the atomic bombs, and will hopefully agree to a peace as well, so that they can scramble to develop their own.
By 1946, if all goes according to plan (big if), Germany will be intact.
Not quite turning the tide, but that's the best that I got.