I think you should try to hunt down a speech therapist in your area who specializes in or has had successful experiences with adults who stutter. I only have your initial post to go off of, but it sounds vaguely familiar. You anticipate what you are going to say, the pressure and anticipation build, and of course you are going to stutter when it comes time to say it. Explanations or descriptions are frequently difficult because there is much less room for avoidance or substitution of words, and getting the message across is important. Again, I could be misunderstanding or misinterpreting something, but it sounds familiar to some parts of my own pattern. People here know what you're experiencing and are generally pretty sensitive to it. Check out some other posts here, try to find a speech therapist for at least a consultation, and be wary of advice from people offering quick-fixes or saying things like "One trick I do is..."; they will inevitably fail you and exacerbate your problem.