Well, for my entire life I always suppressed any thought to do with men or anything like that.
Today one of my two best friends asked me if I was gay.
I said no, but we kept talking... and she has made me realise... I am attracted to men as well as women. It feels... liberating to be able to admit it.
But I am worried about what people will think, and about myself, and about what this means for me.

I personally would find it just another piece of information about you, like the colour of your hair, or what your favourite band is or whatever.
Of course, not everyone willl see it that way. Not everyone will see anything about people that way. Some people will judge you for the colour of your skin, your accent, your wealth, your height or weight, anything really.
Since you cannot control what anyone thinks about any aspect of you why worry about it? People's opinions generally say way more about them than about the subjects of their opinions anyway.

As for what it means for you? Why not just go with the flow and see? For the moment you are attracted to both men and women. That may or may not always be the case. We all change and develop as the years go by. We all have different aspects to us. You just found a new facet. Accept and embrace it but don't make it all that there is, you are a whole wonderful human being, with many different qualities. Love all of you.

Well said by QLP.
Saying 'attracted to men' and 'attracted to women' doesn't mean all men and all women of course, so if at the end of your life you were attracted to many more of one gender than the other, are you bi, or what pigeonhole are you in? What if you live with someone of one gender for many years, while 'attraction' for the other stays in the background, what does that make you? What if in old age another certain person is a comfortable partner around home, and sex is way down the list, what 'are' you then?
Don't try to categorize yourself other than human.
(I'm not even sure about that myself. I like to think I was beamed into my mother's womb from outer space.)

And if you are in a relationship finding a new sexual feeling is no excuse to cheat on a partner either. I would never discuss what sexual expression I am with many people, nor would I want someone that is not a close friend to discuss those with me.

So you did not give any background to your age, your current dating or even marriage relationship

So you believe you had a awaking moment, so?

It is an awakening for me, I have always felt I had to repress any sexual thought about men (though I have had them) my two best friends say they have suspected I am gay for a long time. It shows in my mannerisms, the way I stand, everything, even things I have said (I have had a big crush on nicolas cage for a while now)
Now that I have discussed this with my friend, it all makes sense, and now I am free to fantasize about men... it feels really good being able to think those thoughts freely. I am just worried about the possible consequences of all of this.
Also, I have found myself on many an occasion wishing I was female. I do like being male, but I do desire to have breasts and long hair, and to do sexual stuff with guys. I have in the past for fancy dresses and the like dressed up in dresses/skirts, and really enjoyed it (those occasions it was even my idea to do so).

I have resisted this and kept in in my subconscious for so long, it feels amazing to be able to consciously admit it and to be free to have these thoughts and feelings. I feel so liberated and free and a lot of my problems which have caused me so much pain feel strangely like they have lifted somewhat with this realisation.

I have no boyfriend/girlfriend/partner.

I am 19 years old, turning 20 next (well its this year now by the time zone I am! 2011! Happy new year!)
I haven't had very many relationships.