Are you in the USA?
It is very important she goes to a VET. If she is in this much pain, she needs to see a VET, they may be able to give her something to help with the pain.
If she her dysplasia is so bad, she may require surgery - I'm sorry to tell you but sometimes surgery is the only option left, it is very expensive might will help your GSD.
In the meantime, while waiting for your VETs appointment, make her comfortable, make sure she has a soft comfortable bed and apply some heat (not too hot, just make sure her hips are warm)
Once you visit your VET, he/she will tell you your options.
It is also always very good to give glucosamine and green lipped muscle products such as Glyde GLYDE® FOR DOGS
Good luck and I hope your poor girl is able to be helped.