I am starting to prepare to usmle step 2 clinical skill, my English is very bad, how do I do it?( I passed step 1 and step 2 ( CK) with good score, help me, please.

The only thing to do is practice. Make it as real as possible. Use people you do not know personally and that are cynical and judgmental. It will make it harder and more frustrating. But that is the best way. I practiced a lot and did really well in practice but without the added stress. Then once the stress was put on me, I found myself having a much harder time to put my thoughts together. Practice, practice, practice... And purposefully make it as stressful as possible. That way when you get there, and you have a small fortune on the line, and not to mention the 2015 match, it will not mess you up like it did to me.