The AfD is on the right, but by far no Nazi party. It is doing well because all the other parties are completely nuts, lackin any competence.
There is one very totalitarian party though: The green party. Absurd, but this might shed a light on the success of the AfD.
(btw. Germany did not manage the integration of the former eastern germany very well. This is another reason why a lot of people are dissatisfied with the ruling parties)