At only 1.-1.5 pounds, your little guy is more prone to hypoglycemia. His breeder should have kept him until he was two pounds. That would have made your life much easier.
Food is much more important than Nutrical. Nutrical, karo syrup, pancake syrup, etc, all are just for an emergency, like this morning, when you need to get his blood sugar up quickly. Without a meal of protein and carbs ASAP, he will just crash again.
Giving Nutrical too often just sets him up for another hypo attack as his blood sugar keeps peaking and dropping. You want to keep it consistent until he is bigger and can regulate it better himself. The way to do that is to keep his tummy full.
What are you feeding him? You want to make sure he is getting a high quality food (wet is fine for a puppy) every 2-3 hours, not filling up on treats. You may want to set your alarm during the night so you can check on him and make sure he has eaten.
Did you have your vet give him a thorough check up when you brought him home or was this your first visit? Did he have a fecal exam? Parasites and bacterial infections can make a puppy more susceptible to hypoglycemia.
Here is a great article:
Toy Breed Hypoglycemia