Sounds like she doesn't want to share you at all. I would start some bottle feeding but also continue to try putting him to her. My Nyah had only one puppy on May 3 by c-section. He was premature and we had him in a little incubater on oxygen. In the mean time, we milked the mom. Not an easy job at all. We fed him mom's milk along with Esbilac when we didn't get enough milk from mom. He couldn't latch on so we were using a syringe and then had to go to tube feeding because he was losing weight and the vet said to start that. He gained on the tube feedings. I started teaching him to lap now and eat and now I have the same problem that you do with the tummy being tight. My vet gave him an enema and showed us how to do it. To me it seems like constipation. He still has a tight tummy but wants to eat. We also do alot of stimulation.
As far as the congestion, I agree with Yorkie3. That is worrisome. I would call the vet and have him checked.
I hoped this helped some. You may have to start feeding him on your own. Sometimes some dogs just don't get the hang of being a mom and don't make good moms
But definately have the congestion checked out.