Am I biual?? How do I know?? ?

I'm 16 years old. Im a girl with a girl. This is my first relationship. I only like one girl and it's her. Any other girl that approaches me I don't think about or look at. It's just this one girl. I really like her. I love her. She loves me. My parents nor her parents know about our relationship, but her parents know that she is (her mom hates it, but her dad doesn't care). My parents don't like uality. My girlfriend stays in a different state down the street from my grandmother, so i see her very often (on a regular basis). We are hiding our relationship. My cousin and maybe 3 other ppl on my side know, but all of her sisters, and maybe 8 other ppl on her side know, plus the addition of ppl that see us in public (not that we show excessive PDA). She is amazing. Now my problem is: My heart is telling me yes but my mind is saying no due to the fact that it's religiously wrong. I know the Bible. My stepdad is a pastor. I have strong feelings for this girl, but I don't want to go to hell, but i can't seem to tear myself away from loving her as much as i do. It's crazy. It's like i'm being experimental. Is it wrong to be experimental and enjoying my life?? I really need help deciding what to do. Does this make me bi?? How do I stop this?? PLEASE GIVE MY ALL THE ADVICE U HAVE BCUZ THIS IS REALLY CONFUSING!!!!!! ITZ DRIVING ME CRAZY!!!! HELP!!!!!