"something I did not expect and then my training fell out the window..."
Practice, practice, practice. Anytime you can,in shallow water, go through the skills that make you most nervous.
You must and can and will become confident in solving any problems where you are, not by bolting for the surface.
Stop - Breathe - Think. Then act...
You can program your safe responses to be automatic.
Knowing what to do and how to handle it should give you confidence and help you forget the panic reaction.
Its natural for negative situations to stick in our minds I guess it probably occupies a special part in our brain. If you choose to focus on looking at how you over came that challenge,and reflect on your victory of mastering the drill and finishing the program. I think we should always take time to reflect and celebrate our victories especially after we over come challenges. I think it replaces negative thoughts.
You have to decide on what you want to dwell on. Look forward to a new world of diving and put a period on the CESA drill it is in the past and since some have shared there stories if how they also had problems and moved forward, this should also inspire you to feel better.
Just my two cents.
Frank G
Z GEAR - Z Gear