I had a White Swiss Shepherd. Not a German Shepherd but I'd say pretty close. I got him when he was 9 weeks old and from my experience they are a LOT of work.
Puppies are adorable but they are a lot of work!
You got to do the foundation training like basic commands, socialising, toilet training, being conditioned to grooming and touch etc. I think there's a saying where your German Shepherd will only be so good by the amount of time you spend conditioning the dog during it's first two years?
When my dog hit teenager stage he became a VERY energetic boy. He was running with the Kelpies and he would literally play fetch until he was about to drop. Loved going on long walks, loved going to the beach and he would try to climb trees to be with me or get his ball/toy down.
I could go swimming with him for an hour and play fetch with him for an extra 30 mins and he would still be ready to go and do something else. Loved the swimming part, I would actually kind of swim with him. It was like holding onto his collar and we would swim together, we went really fast doing that.
But he did have an off switch! When I would sit down and paint for a while he would go to his bed and either watch me or go to sleep.
Puppy hood is fairly full on and a lot of work, but I would still keep doing it!
I guess you would need to consider if you are willing to put in all that work and if you can handle the energy.
Also, so sorry to hear about your dog. My dog died just before he was two.