I have considered this question too. You are definitely NOT alone or unique.
I enjoy all kinds of erotica; somtimes this, sometimes that. Among my preferences is “Big Cock” porn; solo scenes, frot, gloryhole porn, etc. I like the hypno, “you wish you were that girl sucking that dick” porn (mostly cuz they usually feature nice dicks, ..... I have come to really appreciate and be fascinated by good looking, big dicks.
But, I have thought about the “bi” thing and I think there is a spectrum within that ..... label? .... too. For example, when I am out and about, in a crowd, going about my life, I never look at men and regard them as “attractive” or not. I don’t think of them as potential sexual partners. I don’t even crotch-watch, DESPITE my appreciation of a naked (and I DO mean shaved!) dick.
The kicker for me is, as has been said, I’ve never had a male sexual experience so, for these reasons, I do not consider myself “bi”. But I envy those who have embraced it and make it work. I do believe if I had the opportunity and access to men who appealed to me sexually, I would definitely be “bi“ ....... often! But even then I’d undoubtedly remain closeted.