And I'm going to agree with Greg and Rob.What is different about playing at home vs on stage? Purely the environment, which in turn affects you at an emotional/psychological level and at a subconcious level too.
It is interesting that in some cases of FD, players cannot perform certain movements on their guitar but give them another similar object, say a tennis racket, and they can perform the required movement without problem. Our internal representation of things is so important in this.
If your mental state is saying 'this is different' 'this is a challenge' or worse ' my dystonia won't enable me to play properly under pressure' or 'I'm probably going to fail' you can guarantee that what works at home will not work on stage.
It's your perception that counts, and this is where you have to do work to oversome this. Ideally you cultivate an attitude of 'not caring' sbout failure but this is tough to do if you are a soloist and in the spotlight. Easier to bridge the gap psychologically with home and stage - eg start playing for people at home, do this casually at first (play for your partner or a friend) then up the ante - invite a bunch of friends round for a evening open a bottle of wine and play a short recital for them. Tell them you are going to make plenty of mistakes, but that is fine because its just a bit of fun.
Be creative , find other ways to bridge the gap - when you practice at home, close your eyes and visualise a crowd of people in front of you.
Buy yourself the Inner Game of Music if you haven't already, its devoted entirely to this issue with lots of examples.
