That's a tricky one. I think a lot of it is a mind thing (you suggested this in your post), for me personally, any level of stress or pressure, and the games over, so maybe even the mere thought of it for you at the moment is difficult and just creates stress/pressure, especially as it is part of your job. Perhaps some bookings with known and understanding clients might help as this might be a far more relaxed atmosphere for you, especially if they knew that you might wish to 'practice' if you were able, but that they understood it may not happen. I will happily volunteer, ha ha ha.
I personally would not assume the service would be guaranteed from ladies such as yourself, just an added bonus if it were, but obviously there would be less understanding clients with expectations.
The best of wishes to you, I hope this is of some help.