From your letter, it sounds like you may be bi, but that isn’t something you should be worried about. Many people are bisexual and feel attracted to or are drawn to members of both sexes. Also, your feelings towards both guys and girls are likely not something that has “clicked” in your mind recently, but rather something that has been uncovered. You didn’t “turn” or “become” bi, but rather you might just be realizing or noticing it now.
As for your friend that you know on Facebook, that is perfectly normal to get excited or a rush of feelings when you see someone you are attracted to. It is also fine that you find yourself attracted to a certain type of guy or girl: a preference for tomboys is no less normal than a preference for blond hair or someone who is tall. You might consider that being excited is your body and mind starting to understand your sexuality and realizing what type of traits you are looking for when it comes to a partner, be they male or female. There is absolutely no need to be worried that you are attracted to both guys and girls though – many people feel the same way as you do and are perfectly happy.
With respect to your Facebook friend being in a relationship, that isn’t something that we can necessarily change, but keep in mind that she is not the only girl out there. There are plenty other people for you to meet and perhaps at this point and time, she is best kept as a friend. Who knows what may happen in the future or even who you may meet. But don’t let this ruin any friendship you have already with this girl – she may be someone you can talk to about things you feel uncomfortable discussing with other friends.
All in all, Calioppe, you shouldn’t be worried or scared about the feelings you are experiencing. You’re not the only one feeling this way, and in time, you will understand more what they mean and what you are looking for in a person.
All the Best,
Brad, for Alterheros