Bisexuality Support Group
Bisexuality is a sexual orientation which refers to the aesthetic, romantic, and/or sexual attraction of individuals to other individuals of both their own and the opposite gender or sex. Most bisexuals are not equally attracted to men and women, and may even shift between states of finding either sex exclusively attractive over the course of time.
Now, I don't know if your bi- or gay, that's up to you, but you will never know that, unless you get out there and date a few girls and find out. Maybe it's not all guys, just this one, and you are bi. But, you have to get out there and experience things, you can't know if your really into girls (or guys) without trying it.
Good Luck, ask any more questions, that's what we're here for.