It was that I knew there was a word for that - bisexual - but I also knew, quite clearly, that I wasn't bisexual. I am monogamous. I have a low sex drive. I am honestly attracted to people of all genders and want to pursue single romantic relationships with them. Clearly, I was not bisexual. There was no decent person, not in my extensive reading and not in my genre television watching, who was bisexual.

THIS. I experienced the same sort of confusion for over a decade.
It wasn't until I'd been out of college for a few years that I was able to really work through these issues, and realize that I was stressing myself out over a totally false dichotomy of an "either/or" view of sexuality. I also had to let go of all the self-destructive biphobic beliefs I'd absorbed over the years.

Great post, thanks so much for saying all this and providing the links.