Confused about "nationality terms" for myself?

Let's try GENEALOGICALLY CORRECT, not politically.

You are an American citizen (nationality) of German, Polish and Irish ancestry. This leaves no room for confusion.

Your nationality = your citizenship. The best evidence of which is your passport, if you are not a citizen of the republic of Ireland, Germany or Poland, then you are not a national of any of those countries. Some people are dual citizens and effectively have two nationalities, however it sounds to me like your nationality is just American. Your ancestry is Irish, German and Polish. Ethnicity (culture) is what culture is a genuine part of your life, food, music, religion, language, traditions and sense of belonging. That's why some people consider themselves Irish-American for example, but really unless it was your parents or grandparents that were Irish, its unlikely that Irish culture is a genuine part of your life, in which case ethnically you should just call yourself an American or (European American to get across the point that your white with ancestors from Europe)

Nationality is the country of ones birth or here they hold citizenship. Your ancestry is the people who came before you and they may have a different Nationality than you do.

Your nationality is your citizenship. It has nothing to do with your ancestry. If you are an American citizen and do not have dual citizenship, your nationality is absolutely nothing but American.

It appears your ancestry is German, Irish and Polish.

Nationality is a political concept, it has little to nothing to do with your ancestors and means the country of YOUR birth and /or where YOU hold citizenship........ so if you were born and/or living in the USA then YOU are an American National....... where your ancestors were born/lived is your ancestry

Your irish German and polish american.