I have 2 horses that are being shown with the extreme cowboy association, 1 is a 13 year old quarter horses and the other is 27. Both of them had the same issues that you have described. I got in touch with Pat Cleveland of the balanced Horse Project and put both of them. Thru her training program. Both of my horses were locked up in their . Withers and their barrels were twisted, in a matter of a few weeks, all of the issues with supplements and motivation were gone, both stop great on their hind ends and are eager to perform at their best due to the fact that they are no longer in pain that even the vets could not locate. I suggest that you contact Pat at the balanced Horse Project on Facebook and make an appointment with her , you will receive phenomenal results. All of your issues are related to the horses structure not being balanced as nature intended. You will be amazed at how soft and light they will be after they are balanced structurally.