Wow - what a great update. Thank you so much for posting. While dog behavior is somewhat typical depending on their form and function - you CO will not and is NOT supposed to behave like a GSD. So, you can listen to your groomer but take it with a grain of salt as the two breeds are worlds away as far as structure and behavior are concerned. Also, do be in such a hurry to medicate and run him to the vet - he is supposed to be a strong and resilient dog - so you have to let him. Of course if his life is in danger then you must do what is needed but please stay away from the vet as much as possible... some will disagree with me but I will stand by that statement. When he really needs veterinary care of course you should take him , but only give him shots that are required by the state - do not over medicate him.
He looks like he is going to be huge - and then you will be in for some fun. There is a thread on the forum about the growth stage and behavior of the CO that is worth reading. Enjoy.