My nervousness

Long time has passed since the last blog entry, and this one brings something new: As you may have noticed, I am writing in English. This is to practice my writing skill as well as to seem a bit more… you know… „professional“. Whatever.
The title says „My nervousness“, and this is one of my biggest problems: From presentations at school and doing things like talking or playing the trumpet in front of an audience through to talking to a girl (sometimes even to my girlfriend!) and to other people I don’t know, I just can’t stop getting nervous. And this is really annoying sometimes. Especially in oral exams.
I mean, if I do something more often, it gets better. For example presenting things in front of my class is no problem anymore since I got used to them as an audience. And also the thing about talking to a girl is quite ok most of the time when I talk to my girlfriend, because I got kind of used to it.
But there are too many things you cannot practice or do that often to get used to it, and those are the real problems. Take for example the FCE exam I am taking. Today was the speaking part, and I practiced a lot with friends, and it went quite good, but when I sat in front of the examiner I just started stammering and playing around with everything I got into my fingers. The two women who talked to us were quite friendly, but this didn’t help.
So if anybody out there knows a solution for my problem, or just anything which helps me not getting nervous in situations I cannot prepare for, please tell me!
And because I am no native and I am still learning this language, it would be very kind of you to tell me about my mistakes and also to explain them. Thanks in advance 😀