Thank you for writing to Alterhéros. I'll try to answer your questions as best as I can.
Reflecting on certain issues about your gender and sexual orientation could help clarify this situation a bit. Here are a few questions I think you might want to think about to understand yourself better.
You say that recently, you feel the need to be male. By that, do you mean you want to be perceived as a man, or that you want to be more masculine? Do you think you would want to be male all the time? Would you want the possibility to switch depending on how you feel that day? Would you miss being a girl? A lesbian? Only you know the answers to these questions, but I strongly suggest you
think about this before making a decision about who you are (ie: transgendered, or gay man etc.).
The impulse to label ourselves can be really strong, but it is not something that always benefits us. If you want to identify with lesbian or transgendered, do it because you want to, not because you feel you need a label for others to comprehend you. You are who you are, and if none of the labels represent fully your identity, then the problem is with the labels, not with you.
As for knowing if you are transgendered or not, I cannot give you a clear answer on that. Here are a few definitions that might help:
Transsexual: Person born a certain sex but that understand themselves and want to live full-time as the gender associated to the other sex (ex: person born female living as a man). (The term transgendered does not always mean the same thing to everyone, so I'm not sure what exactly you meant by this.)
Transvestite: Person of a certain sex that dresses and adopts the attributes associated to the other sex from time to time. Does not want to live fully as this gender.
Genderqueer: Someone who does not refer to themselves as man or woman. Can define themselves as both or neither. The physical aspect of this person can vary, the idea is more linked to social criticism of gender norms, or sometimes just not feeling like the person fits in either option (man or woman) that society offers.
The categories explained above are linked to gender. As for sexual orientation, you say you are attracted (at this time) to both men and women. It's up to you to see if you want to define your sexual orientation by the people you are attracted to, or the people you feel like having relationships with. There is no right or wrong answer. Also, attraction can vary in time. Some people consider that they have a fluid sexual orientation.
You say that these changes have occurred fairly recently. I think you need to take time for yourself and think about this. There's no rush about deciding any of this. I don't know how close you are to your parents, if you have told them you are a lesbian and how they reacted if you have. If you feel comfortable talking to them about this, that's really great. But some parents will not accept the news easily or will say that it's just a phase. This definitely doesn't help in understanding yourself better. If it is a phase, you will know in time, but only you should decide of this. If you are unsure of how they will react, I would suggest waiting until you know for sure that you want to live otherwise than as a lesbian. It will save you and your parents a lot of stress and avoid putting a certain strain on your relationship. If you come to the decision that you should tell them, there are a lot of good coming
out as trans guides on the Internet. This could be useful. Also, if possible, talking to other people who have done their coming out might be a good idea.
I hope this has helped a bit. Of what I can tell, you seem like a very mature person and I have no doubt that you will figure out what is best for you in time. Few sixteen year olds have the self confidence you seem to have about being gay or lesbian. Please let us know if you have other questions!
Kat, for Alterheros