
Hi there,
Had he had another home before you other than just the breeder's?
He's probably feeling quite insecure particularly as he's had little or no socialisation prior to you homing him and this can make some dogs overly clingy to the primary carer in the household. Try to get anyone else living with you to take more of an active role in his day to day needs, such as feeding him, grooming him and taking him for pleasant walks.
It's important for him to learn that the big outside world is safe for him and it might be a good idea to take him somewhere like a wide pedestrian precinct where someone can sit on a bench and let him watch the world go by. The fact that the weather is pretty good just now, garden centres (although not all allow dogs) and pubs with outside beer gardens are ideal situations too. Puppies invariably attract a lot of interest but if you feel he is worried by strangers approaching, ask them not to touch him but just have a few words with you. If he copes with people coming over and doesn't respond in a fearful or negative manner, praise and treat him. When you feel that he's ready, ask them give him a treat (have a bag of tasty treats in your pocket at all times :) ) and if he's becoming more relaxed progress to asking them to tickle his chest or under his chin - always ask people NOT to pat his head - this can worry a sensitive youngster and make them feel threatened. Try to ignore any anxious behaviour on his part as reassuring him can confuse the issue (backing away, growling etc may be read by him as being rewarded by you so become a circle difficult to break).
I'd also recommend that you try and find a local training class for him which will help with his socialisation as well as basic training and commands. If you ask your vet, he/she may be able to advise you and may even know of a puppy class available.
HTH meantime, Regards Teri :)