My 22-month-old german shepherd barks and lunges at other dogs on walks. I pull him back and tell him 'no' but he doesn't stop. He's 80 pounds and I can barely

Pulling him back and saying 'no' does nothing. He's over threshold — his brain is in fight-or-flight mode and he can't process commands. You need to prevent him from reaching that state in the first place. Management first: when you see another dog, create distance before he reacts. Cross the street, turn around, step behind a parked car — whatever it takes to keep him under threshold. Then training: find his threshold distance (the point where he notices the other dog but doesn't lunge) and work there. For most GSDs that's 40-60 feet initially. At that distance, feed high-value treats continuously while the other dog is visible. Stop when the dog is gone. Repeat this 10-15 times per walk for 3-4 weeks. You're rewiring the association: other dog = good things happen, not a threat to eliminate. Slowly decrease distance as he stays calm. If he lunges, you moved too close too fast. Go back to the previous distance and build more reps. This takes 8-12 weeks. No shortcuts.