So your father lied to you. What would you expect. For him to say that he was one of the bad guys? Also, if things were in bad shape there when your father "liberated" it, what would you expect. Germany had been getting the hell carpet bombed out of it for at least a year beforehand. Things were looking pretty grim for the average German citizen at the time. (And things got worse from there)
Another thing is that if you went to Dachau, what you saw was basically a movie set made for propaganda. There was a famous Nazi hunter out there named Simon Wiesenthal. Even he admitted that there were no extermination camps in Germany.
codoh.com › library › documentWiesenthal Re-Confirms: ‘No Extermination Camps on German ...
My father didn't lie and I don't lie. He was in a picture when Eisenhower made the local people go into the camp. And Wiesenthal never was there either.