thanks a lot for the cheering words. You guys managed to convince me that whatever my level is, comparing to what it should be; the key is to keep studying and play the stubborn to get to the level I dream of.
Just answering your questions about the experience I had:
Rodolfo, you are right when saying that I hanged out with other Brazilians. Believe me, I tried as much as possible to get myself into the circle of native speakers and I really succeeded doing that, even making good friendships that will last after I get back to Brazil. The problem is that as long as one is surrounded by Brazilians, it is almost impossible to get rid of them. :-) About the girlfriend, no chance; I am married to the most beautiful woman in the world. :-)
@Dale: thanks for your nice words. They really lightened me up (by the way, another word that I just learned from you).
As far as the other experiences you listed Maria Valeska, I think one of the cause of my disappointment is that I took a friend as my reference. This guy speaks almost as a native (I don't have enough skills in English to say that for sure, but that is my impression though) and he came to the US with no English at all, and after a year, he accomplished this tough task of becoming fluent. So my natural conclusion was that since I came with some knowledge, 6 months should be fairly enough for me. I think I was wrong, but anyway, no reason to give up.
Actually I have no plans whosoever to teach, translate or any other thing related to English as a career. I use it in my daily work, but my main engine is personal achievement.
And Raquel, about my experience here; I work as a system analyst (computer stuff) and my company in Brazil sent me here to help its affiliate plant in the ramp up of a product.
Therefore, I lived the language mostly at work, where I had to drive meetings and discussions. I am glad that I made it well. There was not a single occasion when the language was a drawback (thanks God). I made tons of mistakes, as usual, and got crazy with some of them, but at least I managed to make myself understandable.
Once again, I have no words to thank you all (in Portuguese I might have. :-)
Have a good day.
Ps.: I would love to get emails from you guys. So, follows my address in case you want to send me messages: firstname.lastname@example.org (I know it is weird :-)