Practice makes a man perfect so give importance to your vocabulary and practice it a number of times. Choose some words per day and then after practicing use it in real life when you speak. Try to avoid grammatical errors while speaking. If possible record your voice and find out how you speak and correct you errors. Reading out newspapers and magazines aloud also helps the cause. Listen to the news on tv channels and concentrate on how the newsreader reads the news pay attention on their lip movements and flow of words. Last, but not the least, don't give up your hope and practice it till you achieve success on it!!!
You can get the mastery over the language over a period of time as there is no short cut to it and you will only going to achieve it through practice and regular training and your level of enthusiasm about learning the language as quickly as possible through absorption and learning....