Puppies are especially sensitive to dietary changes. Couple that with having worms, treatment for said worms, and having only been with you for a week, and I'd have to say he's probably fine. Just give him a little time to adjust. I'll defer to others who will no doubt chime in, but if he seems to like canned food only I'd recommend giving it to him, at least for now.
You should also contact the breeder to find out what kinds of food he was eating. If possible, and the puppy seems to like it, feed him that for now, then gradually move him over to a better/different type of food.
Sleeping a lot is normal for a 10 wk old puppy...90%...not so normal. So I'm hoping you're maybe exaggerating a little? Puppies, much like human babies, need plenty of sleep. And they won't act "normal" if they're not getting enough!
I got my puppy at 12 wks old, and she was so sleepy and lethargic for the first few days that I rushed her to the vet thinking she must be sick. They checked her out and said that she was perfectly healthy, but probably suffering from separation anxiety from her litter mates and possibly just depressed. So seriously, I get your comcern...just give him a little time to adjust to the HUGE life changes he's been through. And, do everything you can to make him feel safe and loved in the meantime. Chances are he'll snap out it in a day or two!
If not...revisit your vet, as it is possible something was missed...
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain