So sorry. Had to get a couple of things done by a certain time. Here are my thoughts on part of your problems with your pup for your consideration to use or not. I am not lecturing or anything as I've been exactly where you are so I'm just speaking in plain language that is not to be taken personally or even necessarily directed at you or anyone. It's just for anybody that wants to read it and think about.
Remember first that in nature, the young canines or young of any species are around the mother and any littermates for months as their brain develops and as they learn and experience life so that she or a stand-in pack member, should she die, is around to guide and nurture the young. Mom lets the youngster know when it is time to branch out and leave her be at times, knows when to draw near, comfort. Knows when to discipline and nurture. Most breeders won't keep puppies around with mom for months and besides that, purchasers are panting to bring home the "infant" dog. Why? I don't know but they do. I've done it myself as a younger person and learned the reasons why not in the process and years since.
So consider that you have to try - that is
try to take momma's place and act in her stead for a while. You can't
ever do as well as she and littermates could during infancy(0-14 weeks) but you have to give it your best efforts.
When the infant is separated from its pack in the wild, mother or a pack member gathers it in and it sleeps near or in a heap with its littermates or mother. In homes, we want to stick them in a crate alone often in another room, which is foreign to canine nature. They cry to try to call their pack, their mother, even if they didn't have one in the birth home after the delivery.
It is instinct. They want to bundle with another warm body that cares for them - not be alone as a baby. I would crate that little one in an small airline carrier with the mesh or wire door at one end, pee pad and a blanket near the door end and place it in a chair in or on the bed so you can "bundle" with that baby as in nature, if you want to give it its best sense of security and nurturing. It will still cry and whimper as it wants to be free and out and touching you but with a tiny dog, that is impractical outside the pack unless you have a fence around your bed to prevent it falling off and sleep on rubber sheets in a rubber gown! But it will quickly learn that you are there near, it isn't all alone and vulnerable but in its little "den" and new momma near. It will help it settle to sleep far sooner and with a happier sense of well-being.
Keep Nutrical or whatever you use for potential hypoglycemia nearby and if the puppy won't rouse or exhibiting any of the symptoms of low blood glucose, use that.
In a separate post I will give you some things that have worked for me for when you do have to leave your little one alone - again a foreign concept to the nature of the infant or youthful canine but something "new mommy" can help teach them to handle without overly stressing.