Many Chinese students who have learned English for more than ten years are still unable to speak English fluently when they meet a foreigner. They seem to have mastered the basic language structure, but a conversation in English will make them feel uneasy. They are afraid that other people might find out their mistakes.
It is not uncommon that many students, who are bad speakers of English, can write English perfectly. This proves that they are not able to organize their ideas in English. The center of the problem is that they lack practice and confidence.
Why should you be afraid? Do you fear those foreigners with whom you are speaking? Don't be shy, they will not laugh at you just for a small mistake you have made. The best way to get rid of this trouble is to learn to speak by speaking more. I am sure that constant practice will help you to succeed.