Marty, I haven't read all the posts here and I imagine someone has already suggested...........keep him stalled............a good bedding of shavings with a layer of hay over top will give baby hay to lay on but not so much for mom to eat.
I would be REAL suspicious of joint ill. SMZ has been the med that has worked well for me. I am unsure of giving Banamine to one that young without the vet approving that. I wouldn't worry so much about him being sore as long as he is nursing well. If he stops nursing then banamine for sure. Gotta keep him hydrated.
Be sure to keep a record of his temperature. At least 2 x day.
He really needs to be seen by a vet or have meds prescribed by a vet. If joint ill, can go down hill fast if he goes septic........not trying to scare you more, but he really needs a vet exam.
Geez, I'm so sorry you are having this with your little boy.
I'm hoping it is just a 'strain' or sprain or some such, but I always look at the worst case.
Joint ill is usually real quick to correct if treated early.
Thinking of you here.
Charlotte