A number of people feel that sexuality is fluid and exists on a spectrum. Have you heard of either the Kinsey scale or the Klein Sexual Orientation Grid? You can find online tests for both of these. Although they're quite simplified and you can't have your sexuality determined by a test, you might find them helpful anyway. I would personally recommend this one, because it highlights the differences between things like sexual attraction and sexual behaviour.

I understand that you are feeling overwhelmed and upset, and it is understandable that you feel that way. Taking time to really be honest with yourself and be introspective is important. Is there anyone you can talk to about what you're going through? Discovering that your sexuality isn't what you thought it was can be scary, but it doesn't have to be a horrible experience.