There's a saying that democracy is not when a government gets installed by fair elections, democracy is when a government gets removed by fair elections.
Hitler was democratically elected as well, that is not sufficient to label his regime as democracy.
No he wasn't, it is not that simple. His party at that time had no majority despite being the largest one. He got appointed chancellor not by democratic vote but by backroom negotiations - mostly because he was expected to be easy to control.
From this state he went for the dictatorship but again not by democratic election but rather by scaring the other parties into voting him the Enabling Act in 1933 after the supposedly communist-inspired Reichstag Fire.
Hitler was democratically elected as well, that is not sufficient to label his regime as democracy.