They may have white supremacist sympathies, and they're on the defense because you're clearly rejecting white supremacy.

However, you should also ask yourself how much of your rhetoric is performative. When you go out of the way to say that you're ashamed of your ancestors, what is your objective in saying that? How is that more beneficial than simply saying something along the lines of, "Well, my family didn't raise me with appreciation for the European cultural traditions in my bloodline, so I simply feel a lack of connection to those ethnicities..."