Hi Bluesguy's Human.
I'm sorry to hear about your furry friend's distress.
A hard stomach isn't normal.
You need to take him to a vet as soon as you can. He may have a blockage which could get very serious very quickly. You don't want to wait and see what develops. He's already constipated.
That's not the only thing it could be of course. He's been through the trauma of moving and a plane ride and now a new place. Was there no quarantine involved? Has his food changed? What is he eating? This is information your new vet might want to know. If you've got his previous medical records take those with you. You're probably not going to have a stool sample (less than 24 hours old) but if by miracle you do, the vet would want that. Sometimes the cause of this is a parasite.
So, we don't want to guess or wait. Let's get your cat checked professionally.
I hope he'll be good as new soon. Please let us know how things go.
thank you so much! ill be sure to do that as soon as i can.