Quinn's Re-Training

The last time I posted (Wow! Two years ago.) I mentioned Quinn was a little shy in PetsMart and had some issues with over-reacting around unfamiliar dogs. Though we've been in competitions and he earned his BN (Beginning Novice) title, we now have to go back and address his issues.
My goal is to earn his RE title and move on to more obedience (Novice, Open and Utility). So to actually succeed, he needs to learn to calm down around strange dogs.

The first and last time I tried to compete in Rally Excellent, he really went nuts over the Dachshund that was supposed to be working in the ring while he did his honoring. Luckily, we found this out before going into the ring. I pulled Quinn, not only did I not want him to practice the behavior, but I didn't want to mess up the other dogs chances.
The one thing I've learned is 'out of control' dogs push Quinn's buttons. The other thing I've learned is that many of the dogs in Rally are out of control. They don't really know how to heel and if their owners couldn't use fake lures, the dog would be gone. (Yes, I expect some will take exception to this, but I've seen a lot of dogs that shouldn't have qualified, get their titles-- Missy is one of them!)
So, I've decided to work with a trainer. Intellectually I know what to do. I've helped many other people with the same issues. But knowing and doing are two different things when it's my dog that's acting like a fool.
We met yesterday at PetsMart, he wasn't interested in meeting her at all (that's fine). So she and I talked a while, I told her his history and she watched us walk through PetsMart. I don't know if it was lucky or not, it was very quiet, not many dogs or people. After a while she told me what I was doing right and what I needed to work on. Yay!
One of the things I had thought I was doing wrong was corrected him when he went over the top and began barking. She told me to keep doing it. I had been moving back while correcting him, she told me that I shouldn't do that. Keep him in place until he calms down and make moving away a reward for calm behavior. Wow! Such a small thing, but it really makes sense.
She brought her dog in and we worked on getting him to just allow them to move around us. He did really well and as we left the store we walked out together. Quinn and her dog were about 4-6 foot apart, but Quinn was ignoring her dog!
I do have to admit, I put Quinn away, got into the car and cried.