My dog does not have hip dysplasia (thankfully), but she has had two knee surgeries and both elbows have had surgery. She's a bit of an orthopedic train wreck. I would really, strongly urge you to consult a board certified orthopedic surgeon about your dog. They will be more expensive, but they can give you a much better idea of what exactly is wrong and how to proceed. If you do decide to do surgery, I cannot stress enough the importance of having an ortho surgeon do the operation. Regardless of how wonderful your regular vet is, they do not have the same level of skill and expertise an ortho vet does. My own super awesome vet is the one who urged me to see an ortho specialist in the first place, and I have been SO glad for Riddle's sake I did.
That said, there are a lot of options to help manage pain. Glucosamine supplements (my own personal favorite is
InClover's Connectin) should be started right away. Physical therapy would also not be a bad idea, to help keep up good muscle mass to support the joint. Pentosan is an injectable that can help a LOT with joint issues, it has certainly made a difference for Riddle! Adequan is another, but honestly I've gotten the same results with Pentosan and it is much cheaper than Adequan.
Try to get your girl to swim during warmer months too. Swimming is excellent exercise and very low impact, so she can do a lot of it without hurting herself.
Other things you can do are purchase a ramp or stairs for the couch/bed, and teach her to use them instead of jumping up and down. Lift her in and out of the car or use another ramp/stairs. Drop a chunk of change on a really nice, orthopedic foam bed. Good, supportive bedding seriously makes a world of difference for joint issues.