What exactly is my sexual orientation?

Ok, so im a girl and i keep getting confused at what sexual orientation is. At first i thought i was just straight but now im no so sure. I always been attracted to guys but at times i think been attracted to girls. Ive fantasies about both of them before in the past. When i was younger i used to try and block out the girl ones but it dont bother me at all. Ive also been attracted to a transvestite before (blame rocky horror). I like to read books and fanfiction and ive been turned on by what i consider great coupling it dont matter if theyre straight, gay, lesbian ect I want to be sure what im attracted to but i dont want to just "experiment" cus i dont want to hurt anybody. Emotions are a big thing for me (I have Emotional Overexcitability). Plus when i think about relationships in general its not gender i think is important. I believe that if two people truly love each other then they should be together. When imagine me in a relationship all i want is to be with someone i love and who loves me just as equally. Im so confused, please help me.