Hallo! Sei gegrüßt!
Your story reminds me of a girl when I was at school (some decades of years ago). :) Am coming from Cyprus and at our school we were studying foreign languages. This girl that am talking about was not a good pupil at all but when she had to talk in another language she was using it no matter how, instead some others, being perfect pupils in written language and in the class, were not so good in spoken language as they were afraid not to make a mistake. What turned out at the very end was that this girl she could speak better a foreign language than the other ones.
I wouldn´t say that you have lack of confidence but you are rather a perfectionist and you don´t like to make any mistakes. My husband was telling me the same thing for himself some days ago.
He is a German citizen and he moved to Cyprus in 2004 because we would get married and decided to live there. Unfortunately, in 2006 he lost his job and in 2007 he was offered another one in Germany so he had to move back to Germany. In January 2007 we were blessed with the coming of our baby boy and, unfortunately, our baby was growing up without knowing his dad so in November 2007 I decided to quit my place and my job and come to Germany to join my husband so that we are all together, as a family should be! The problem is that the town where his job is it´s not a touristic one and people here they talk at all English! (The town is called Braunschweig and is near Hanover). That is quite frastrating because I can´t do anything and I can´t go anywhere alone because I don´t know any German at all. I started some months ago studying alone from another book and audio cd´s but with a kid running around all the time was not so easy. I´ve recently purchased the Rocket German with the hope that I´ll be able to learn faster as I tried the 6-Day Course and I found out that it is very well explained. Well, so far I found it easy because as I said I was studying from another book so all this is quite familiar to me and much of what I´ve been able to cover till now I already knew it. I will see how I´ll get on with the more advanced and unknown to me words and phrases.
I need to learn German very fast not only because I want to be independent and not need to count on my husband all the time but also because of my child. Soon he will start talking and soon he will have to go to the kindergarden so I need to learn the language in order to understand what he tells me.
Last month we moved to a new apartment and I started using some of my German (no matter how) with some of the neighbours here. I ask my husband many times to tell me how I should say something and then I use it (some times I forget something but they show to understand me). Last week, we visited my parents-in-law and I used again my "so far" German. Later my husband told me that they were quite impressed from my German knowledge and he was as well. He told me that, unfortunately, he is not the same concerning the Greek language. He is just like you. He is afraid to say anything in Greek with the fear not to make a mistake. But this is wrong because if he doesn´t dare to talk he will never speak Greek. And so you too. You better start talking with the people around no matter how you´ll say it. Slowly-slowly you will learn how to express yourself correctly. Try it, what do you have to loose? Nothing.
I apologise for my long message but I thought to let you know about my personal experiences in order to help you.
Good luck then with your German and do let us know how you proceed. Be sure that I´ll do the same.
Gute Nacht and Bis Bald!