If teeth aren't the issue in all this of course.
I am glad you have been able to recognize that you may be rushing things and are taking steps to correct the approach now. That is a quality you should absolutely be proud of as a horsewoman!
I have an AMAZING little quarter horse mare that I wish I would have given another year to instill better technique in the pattern, hauled more and time onlied a little more before asking more of her. I am VERY lucky she turned out great and had a mind that could take the amount of pressure she endured at such a young age with a very immature horse person as I was back then. I am happy I have grown from that and let her take the time later in her life and smoothed things over.
Keep your chin up, training can be so boring sometimes as consistency is key with horse training especially barrel horses. You WILL get there and be able to run soon enough and you will be so happy when you do achieve that goal and you and your horse truly have the technique down.
Good luck girl!