Stan, I agree with Montana/Scott that you're on the right track. I've learned a lot in the last year from some great natural horsemanship trainers here in Missouri USA - who also just happen to be skilled horsemen/women and Parelli-trained trainers. The amazing thing is when I watch them do whatever it is we're doing, it seems so simple. Then, they watch me do it and can see all types of small differences which limit my success. I swear, there are such subtle clues the horse picks up on. For example, the trainer pointed a finger that I didn't notice - that finger makes all the difference in sending my horses in the direction I want. And, Stan, make sure it is your pointer finger, not the attitude finger! The horse can tell the difference!
Another example, I was working on my young horse, sending him forward or in circles, such as you would need to do if you were to have the horse load himself into the trailer. I was glancing at the horse's hip instead of shoulder. He stopped. I looked at his hip to see why he stopped and he swung his hindquarters around. Well, I found out that looking at the shoulder makes the horse want to go forward, but looking at the hip means stop to the horse. So, they can tell the difference -- and now it's my ongoing lesson -- don't look at the hip! So, it probably feels like a lot of work ahead, and you're very disappointed that you've missed out on a lot of fun trekking this year... but I promise you, when you get the combination right, and Stella realizes that the gig is up, you will be very pleased at how well you and she can work together and I bet you see a big change in her attitude. This type of training may be a good investment with Bugs to get you both off on the right foot and helps you figure out which horse you're going to be riding in the coming weeks on the treks ahead.