I am so sorry to hear of your dog's hips not doing well!
My dog Nigel (a Saint Bernard/Bloodhound/boxer mix) has really bad genetics when it comes to hips... two of his brothers were diagnosed with hip dysplasia and several other of his littermates have a lot of trouble getting around. Since I found out when he was still a puppy, I have kept him on some supplements which I believe help a lot. The first one is vitamin C, I give it to him twice a day. The second is glucosamine, and the third is MSM. So far, so good with my Nigel.
A friend of mine has a shepherd diagnosed with very bad hip dysplasia. Since she started giving vitamin C and glucosamine, her dog Napoleon has been getting around great. Her vet couldn't believe the improvements, and told her to "keep on doing whatever you are doing, 'cause it is working!!!"
Best of luck to you whatever you decide to do, and know that you are not alone.