I can appreciate you really wanting to learn so as to avoid more big mistakes in the future. The smart thing would have been to rechearch as much as possible for years before breeding -but nobody's perfect. The most important thing is to learn from your mistakes.
A smart thing for you to do at this point would be to really 'follow-up' on all the pups you sold.
There is no other way to know their true characters and what you bred.
Aside from learning alot in this way, you should also learn to feel very, very responsible for them (even if they aren't yours anymore).
Following up on the puppies (keeping in touch for years with as many as you can) is the ONLY way to show you what you bred (the good AND the bad).
This is hard work -and one of the many reasons most dog lovers DO NOT breed.
Surely, the way they are raised is crucial to temperament but you will still learn alot when there are enough puppies to compare. Do NOT have faith in 'puppy-testing' in really means next to nothing. "Parent testing" is the most important thing -and following up. You don't need to visit them all the time -just a few times each year with a list of questions for the owners and a couple of smart 'tests' for their/your dogs.
Even seemingly PERFECT parents shouldn't be bred if their puppies 'follow-ups' show that they pass on regressive faults, or personality faults of previous generations. I know a Giant Schnauzer breeder who will NOT breed his BEST dog because the puppies of his two first (and only)breedings grew up to be TOO dominant. And he has been offered tens of thousands of dollars to change his mind...
What I am trying to say is that it is very probable that ALL the pups you just bred have bad nerves -one just began showing it earlier.
This is the way it USUALLY happens actually. Rarely are ALL the pups nervous wrecks at 2months old.
I have seen G.S.D.pups from a very similar breeding that seemed impressively tough and brave at 2 months but by 6 months had NO tolerance for new experiences. I followed the pups (five in all) till age 6yrs (just out of curiosity) and they were all a sad waste of anyone's time, 3 had very strange phobias too(ex. phone booths!). All were remarkably stupid dogs and problematic even as pets. Any mutt off the street would have been better for each family. That's what I mean by totally worthless.
I hate to say that about Gods creatures (I am Christian too) but GOD didn't make these dogs a MAN did. If God had his way, both parents would be dead because they didn't have the temperament to survive on this planet and if bred would have 'weakened' his better creations. This could start off a whole new debate because MANY breeds are practically man made and ailing and weak on purpose-are THEY all a waste of time? I can't say really-
does God recognise breeds?
But this is just my point: We must take full resposibility of our breedings and leave God out of it. Just food for thought. I wish you great luck in your future endeavors...
Dogs are not our whole life, but they make our lives whole.
--Roger Caras