My guess is he swallowed something that is now stuck in the esophagus. I would try to get some coconut oil down him or egg white, which would be even better. But whatever it is that's stuck, may not make it through his gizzard. I have a hunch this little guy may be dead by morning.
If he makes it through the night, a vet might be able to surgically remove the obstruction.
If he makes it through the night, a vet might be able to surgically remove the obstruction.