Without a Nazi defeat I wouldn't exist since my paternal grandparents met in post-war Germany, but if I was put into that situation I'm 43.75% Irish, 25% Czech, 6.25% Danish, and no idea for the other 25% (the 60s were a crazy time). Saying that I'd probably try to downplay the Czech (mom's side) and overplay the Irish and Danish (dad's side). I haven't heard much about how the Nazis viewed the Irish, but it'd probably be something like a lower class. I can't see Hitler hating the Irish the same as he hated the Slavs or Jews. My Slavic grandmother did get out of Czechoslovakia in the 30's because of the Nazis so that might cause some problems.
I could probably then either be on the European Continent or in the U.S. If I was in Europe, I might end up back in Ireland not matter what. Hitler might deport Irishmen on the mainland back to Ireland, as to not "contaminate Germany with their blood".
Ireland could potentially find itself under a British Nazi puppet though, in which case I'd probably be treated even shittier than under the Nazis ironically. An Ireland directly under the Nazis would probably be economically shitty, but at least wouldn't have the racial persecution that you'd see under a Nazi-British Empire. In a Nazi US I'd probably be seen socially just the same as I would in a directly Nazi controlled Ireland, but I'd most likely be in a better economic situation, as Hitler would care more about his American puppet than Irish puppet.
Given any of those options though I'd rather just go to some remote location in the Irish countryside/British Columbia and raise sheep or something for the remainder of my life. If I was the same person I am now and born in a Nazi controlled world however, I would have probably tried to lead a resistance when I was 14 or 15 and ended up in a work camp somewhere or dead, probably dead.