Economics

Equating fascism to Communism originates from Nazi apologia called Double Genocide Theory. The Nazis invented industrialized mass murder, whereas the Communists made dramatic strides for the Working Class, including a mass democratization of the economy, lower wealth disparity, a robust and free healthcare and education system, and more.

Essentially, you're trying to replace actual historical analysis and statistics with emotional scaremongering based on an anecdote from your Nazi-sympathizing grandmother.

Moreover, the DDR actually had it worse, it was made to pay reparations for World War II while lacking a real industrial base, which was mostly in Western Germany. The Soviet Union was devastated by the Nazi's genocidal assault on the Slavic people's they deemed inferior, and therefore couldn't afford to rapidly rebuild the DDR or financially support them as much as they would have wanted.

I recommend you take some time to read historical accounts and genuine criticisms of the Socialist system, without just vaguely gesturing at it.