In my opinion the problem is that in some countries like mine, Spain, the English has been taught focus on the writting-grammar part. If we dont practise the speaking part very often we are afraid of make mistakes when we talk and we can´t express ourselves at all. I think the only solution is don´t panic and talk ( even if we make mistakes) I mean first at all we have to focus on say something and then we will focus on how we are saying that. 

Start fresh. Start anew.
Don`t be afraid of ``lowering`` your level to get simple, non-complicated, not-so-fancy, phrases.
Pick up some lines from a TV show you like and repeat after the actors, or even at the same time if you memorize it.
Talk to yourself slowly. Read aloud slowly.

Know your mouth. Discover the `englishn sounds` you can and those you cannot do and work hard on that.

I`m not a professional. But I think it may be helpful.

got* (italki really needs an edit button)

One of the things that worked best for me was to memorize a short clip of your favorite tv shows. Rote learning is best when it comes to learn speaking a new language, and it is apparently painful and long a process. So you need to find something you can enjoy. Memorize 5 to 10 minutes dialogue could be very effective but you should start from only one or two minutes (even one minutes dialogue can be tough to memorize if it is something like Big Bang Theory lol) 

For some reason Ghazal for more answers when she asked the same thing yesterday, have a look! http://www.italki.com/question/334487