How about a pinch collar? Your trainer can show you how to use it because it is tricky to use and you have to know how it's done correctly. I know it looks horribly cruel, but one of our trainers advised using it. I was so against it, but it has done wonders for Shiloh. Maybe our dear little LoganII has a bit of separation anxiety! Who can blame her!
Be very careful with your back! I hope therapy works!