I am so very sorry about your boys accident, It is possible he has a concussion or just a vestibular disorder:
Either of these should get better as swelling in the head goes down and the brain returns to normal. He may be disoriented for a while. Cats are great healers.
As long as he is eating and able to potty just give him some time.Ask your vet if he wants to try a steroid to reduce swelling. Or an antibiotic to prevent infection.
Please let me know how your boy is doing.
Best wishes and prayers for a complete recovery,
It is my pleasure to help someone as lovely as you and your sweet baby.
I will always be here for both of you.
Thank you for your accept.
I will be praying for him so please let me know how he is doing.
I am praying for him!!
Please keep me posted.