It is possible that I have austrian ancestors

[Der/die AtheistIn]

My dad was born in a village which was colonised by austrians during the Austrian-Hungary empire. I know for sure that some non blood relatives have had german names, but I don't know if I have austrian DNA. I don't care much about this, but my father sure does.Romania used to be communist, then the regime has sent some austrian minorities to Siberia, including an oncle and an aunt of his. They were eventually sent back during dad's youth and he heard from them what they've been through. Today he told me this, for the millionth time (he didn't repeat himself 1 000 000 times today, he repeats himself since last two years). He also said: "We have austrian blood so we have all the rights to live there and be catholics. Many germans don't know how it is to suffer because of your nationality. I hate communists for what they did. My oncle and aunt were both orthodox and catholic, so if we should keep the tradition on. I would be very happy if you became both orthodox and catholic. Only if you want to, I'm not forcing you!". I'm kind of happy he doesn't force me, but if I were to refuse I don't know what arguments I can bring. I can't tell him now I'm atheist, since I'm not financially stable. I thought that maybe I should go to Catholicism now, to make him happy, and tell him later I'm atheist.
I do agree that the communists were assholes, they've sent people to concentration camps for simply being of german heredity, but it's the past, we should move over. Father is still suffering about this. If it's hard for him to get over this, why doesn't he seek help? He has a family, we are willing to help. He can go to a therapist. He does this to all things that make him sad, instead of trying to move over, he keeps them inside and then bursts.
Also, the austrian pride part makes me wanna laugh, having austrian DNA doesn't automatically make anyone awesome. In fact, dad doesn't show many austrian, or german, stereotypes for that matter.