Dear Rabbi, The founder of Shavei.org recently said on Israel National Radio that there is a particularly large interest among Spanish and Portuguese peoples about their Jewish heritage. I know an Orthodox rabbi that believes I am part of the Anusim of the Inquisition. Interestingly enough, my sister and I independently found ourselves interested in our roots. I have started to search my family tree and both sides have almost all known Sephardic surnames. And the DNA from my mother’s side originates from the Iberian Peninsula area, which I understand is the same Sepharad of the Bible in Obadiah. For an individual family, what constitutes "confirmation" of one’s Jewish ancestry? I cannot imagine it will say it on any birth certificates, and the only family tradition I know of is a rabid hatred of Catholicism. And what does it mean that so many Sephardic names are common to Hispanic people?
Unless we have a valid witness of a person being or known to be Jewish, we can't really know. In your case you might definitely be from Jewish lineage, all the signs you listed and more will indicate that, though that doesn’t make you halachacly Jewish. If you wish to be part of the Jewish people you should contact the orthodox Jewish authority near your place to see what conversion is all about.