Just saw this and thought I could help. For a working shepherd you have the right idea, but I just saw a few small things! This isn't perfect either, but I just thought I'd point out some stuff I noticed. References are always helpful when trying to draw specific dog breeds.
> Broader snout - german shepherds have pretty thick muzzles
> Slightly bigger ears - GSDs have giant bat ears. The way they were drawn is fine, I just did the ones on this in my style.
> Shorter back - the steepness is fine (working GSDs have pretty straight backs), but it looked a but long to me.
That's pretty much it! I also thickened the neck and deepened the belly a bit. Your original reminds me a bit of a coyote - too lean and lanky with narrow features. German shepherds are pretty stocky, especially muscular or longer haired ones.