I used to get P.W.M when I was doing an English course and from time to time I had the same feeling as you. However, end-of-term exam's contents are limited to what you have studied in duration of a specific term and passing with flying colors counts a lot because it shows you have fully learnt the material. As for speaking fluently, I should say that it cannot be attained over night and you have to be patient and work hard with ruthless determination to see the result. It’s been four years since I started but I’m still having difficulty in writing a simple letter! Learning a language is always difficult.