I respect your status as an adult, but please don't be offended if I point out that 18 is still very young. Your feelings may settle down to something simpler as you get older.

Having said that, human sexuality is very flexible and there is room in the world for everyone. I don't think labels are at all useful except on dating sites. I myself am a bisexual man in a stable monogamous heterosexual marriage. And that's no one's business but our own.