From what you've said it sounds like you get it right on easier runs. So you know what to do. It's just a confidence thing. Just keep at it bro and you'll get it.
Many people wont agree but I used to find the quickest way to build confidence on black runs was to ride something well beyond my comfort zone. Riding double blacks (although not riding them well, and not something narrow either) would give me a huge boost in confidence and control when going back to black runs.