I see where the problem is now. You don't know history, or rather, you accept that history is "one volume of a thousand volume story".
You say that's not possible that Ukrainians supported Nazis, because they were part of Soviet Union since 1922. You basically reject any possibility of them being on German side, because it doesn't make sense to you, and since it doesn't make sense to you, it didn't happen. That's funny, since it's exactly what happens. Imagine how good Soviets were for Ukraine, that they were collaborating with Nazis against them. The horrors they suffered under Soviets before WWII, is exact reason they supported Nazis, and Stalin's punishment for their role in WWII against the Soviets is main contributor to their pure hate for Russians. Side note: The only nation that hates Russians more than Ukrainians are Poles, and they couldn't wait to become part of NATO. I think they would love to get back their territories in Belarus and Ukraine that were taken away from them by Russians.
With independency from USSR in 1991, the hate toward Russians they were holding inside was revived with creation of several nationalist groups, supported by no other than good ol' USA. I wrote about it in other threads, and I'll try to find it and link it, but for now, I recommend watching this documentary that may expand your knowledge of history. I am not asking you to watch whole 90 minutes, but first 15 minutes will give you better insight of what I am talking about. Also, it's age restricted, you may have to watch it on Youtube.