I have been having problems with my barrel prospect lately.(It's my fault) He does the barrel pattern beautifully at a walk, ok at the trot, and absolutly horribly at the canter.

My old horse was a finished barrel horse, so I could just sit there and let her do her stuff at shows, and I never worked her around barrels at home. So, I have no idea how to train a barrel horse. I am going back to school in august, and to get into the college I want, I have to compete and do well in high school rodeo barrel racing. (So I can get on their equestrian team) So, I have two and a half months to get my gelding running barrels well. I fell totally stupid, having no idea how to help my sweet horse. I think that this might be a hopeless goal, and I would be majorly outclassed at the rodeos. How can I get my gelding to run barrels well?