Japanese internment camps ended immediately after the war. And while a terrible stain on America history, are nothing compared to Nazi extermination camps or Japanese camps.
The gulag system certainly predated WWII, and certainly continued after. The soviet regime was certainly brutal and commit mass murder. Lenin, Stalin and subsequent soviet premeires have a lot of blood on their hands.
But the reason the soviets came into Germany with a vengeance is because Nazi advancing troops certainly took little care to minimize civilian casualties because the plan all along was to exterminate literally all of eastern europe and colonize it with Germans. The Jews and the holocaust where simply stage 1 because Hitler and the Nazis feared and hated the Jews where as they saw Slavs as so inferior they could be killed after the war.
The Nazi industrialized genocide as a precursor for a much larger planned slaughter and enslavement of all of Europe. Now you might say, that was the Nazi leadership. Not the rest of the nation. But that is crap too. There were 3000 or so camps in Germany proper. Millions of people helped build, run, dismantle these camps. Many more helped with logistics or saw the cattle cars go one way full and come back empty. Many had not problem grabbing their Jewish neighbors property.
Antisemtism was casual and wide spread. The nazi political platform was not subtle. All of the above, the expansion, and colonization of eastern europe was laid out in Nazi propaganda. Lebensraum was not some hidden agenda. It was state policy.
I am sorry your family was likely killed by advancing allied and in particular soviet troops. The rape and murder of civillians is never excusable. But to compare Japanese Internment to the holocaust? Or to German front-line atrocities? Nah.
Soviet comparisons are harder, but suffice to say, Stalin never planned or tried to implement a plan to murder half of Europe. And as awful as the Soviets were, they never approached the brutality and indoctrination and bloodthirsty aspirations of the Nazis. But more importantly, Stalin never saw entire peoples as subhuman and requiring extermination. Yes he had purges and yes he caused great atrocities like Holodomor but he was not trying to wipe out Ukraines as a whole for example.
No one is saying Stalin was a good guy. And same with Mao. And same with every other major dictator. But the Nazis (and Imperial Japan) for that matter were a special level of evil. And that the people who elected and supported them and kept them in power suffered when their evil regime came to an end - its still awful, but it does not change the fact that its not comparable to the atrocities of their own government.