My understanding is that they learn how to play as puppies as they would get feedback. So you may consider exaggerating when it hurts to better highlight the pain. Alternatively, another puppy to play with.
Someone tried to explain this to me once. They said that the original formulas for insulin are really cheap, it’s just the manufacturers have all agreed to only make the expensive formulas to maximize profits since it’s not in their best interest otherwise.
Maybe check your vitamin levels and make sure you’re drinking enough water. Sugar is dehydrating, a general rule I follow is drinking 2 cups of water for every cup of something else.