I am sorry your dog is having so much trouble. X-rays are great for evaluating bones and joints, and sometimes even soft tissue but it sounds like your dog might have something going on that is beyond the capabilities of the x-ray to evaluate. I am particularly concerned about his knee, the cruciate. Dogs that tear this ligament are typically pretty uncomfortable, and usually don't want to bear any weight on the leg at all. Occasionally they may toe touch for balance, but generally the leg is kept up and off the ground. A torn ACL is often repaired surgically. Please see the following website for more information on this issue.
I think you may want to call your vet in the morning and let them know your dog is still not comfortable, in spite of the pain medicines and anti-inflammatory. Let them know you are concerned about his knee. If this is a knee problem, diagnosing it and fixing it ASAP will mean alot less discomfort for your dog and an easier recovery. Please let me know if I can be of further assistance. If this has been helpful, please hit the green accept button. Best of luck with your handsome man, I hope he feels better soon :)