Confused about sexuality - male, 27

All my life I've been sexually attracted to girls and watch heterosexual porn, but for some reason my heart flutters around some men and I struggle to make eye contact. I don't know if it's anxiety or attraction. I don't watch gay porn or have any desire to. I'm so unhappy and don't know how to figure it out. I've been on lots of dates with women and it seems to have no meaning.