Confused

For 3 years now, I've thought I was bi-sexual, but now I'm sort of confused. To be bi, do you have to be sexually attracted to females and males, or can you be sexually and romantically attracted to one but only romantically attracted to the other? I know I'd never be comfortable doing any sexual with a female, aside from like kissing and things like that, but I'd go further with a male. Am I still bi? How would I be able to tell my female crush without confusing her and making her uncomfortable?