Avoid the high sounding words while trying to communicate in English,choose simple, easily pronounced words.Repeat what you want to say in your mind,be calm and articulate during your utterances ,Speak in simple clear sentences.little by little, your vocabulary storage develops.

Get an english teacher... You don't need vocabulary to speak well. English is about tenses, stop thinking its hard work, your mentality also counts...just say wat comes to mind in the simplest possible way.. The best way to learn any language is to get a private tutor...someone to communicate with.. Its not as hard as you think...