You were right in not drugging him. It would of been a very hollow victory.

It sounds like your horse just needs to get out to more shows in general.
Anyway that you can haul to fun shows an just work him until he settles himself?

"Blessed are the flexible for they shall not get bent out of shape"
"You can discipline and Discourage or you can Discipline and Encourage"
"Gentle in what you do , But firm in how you do it"