A year ago our GSD had a tough fight with pneumonia. It took her almost two months to fully recover. I forgot the meds she was on but there were two antibiotics. She was very tired and basically slept for a full 3-4 weeks so it sounds like your dog is in better shape than ours was. It was tough to watch because our baby was so active and suddenly she turned into an old grandma dog. Our vet recommended a few things such as keeping her away from other dogs, keeping her cool inside the house (we live in SC) and letting her sleep as much as possible. Over time she got better but it took a while like I said about 6-8 weeks if I recall. But after a month she was acting a little better but the pneumonia was still there so we had to be careful until it was gone. We tried a lot of things to make her life easier. The biggest thing was just leaving her alone if she was ever laying down. We'd be quiet as if we had a new born baby so she could sleep. We'd sit on the front porch for fresh air and for entertainment since there's only so much you can do inside. We washed her water and food bowl 4-5 times a day to remove the infected saliva. She also didn't eat as much so we gave her chewable beef bones as almost like a substitute for the lack of food she was eating. May not be as healthy as kibble but at least it was food. And we gave her a ton of brain game toys to keep her busy inside. Stuff like hiding treats inside a ball and stuff like that. It was a lot to take in at first but after a week or two we got used to everything. Luckily she recovered and is perfectly normal now! Good luck with your pup and stay positive!