Bald kitty

My 3 year old cat became very ill a few months ago but recovered. His behavior changed to where he would run outside and stay away for a few days (he's been neutered for 2 years). When he returned the last time I took precautions so he cannot get outside again. Now he obsessively grooms. He's practically bald. There are no fleas. There have been no major changes. He eats and drinks. He won't play. He just grooms. Any suggestions?

I would get him to the vet.  He needs a thorough check up to see what could be causing the excessive grooming.  It is often too difficult to tell what is going on with cats just by looking at them.  Please take him to the vet.

I did take him to the vet long before I started seeking advice from this board. My vet feels he is still stressed from being so ill. I am looking for suggestions to get him to stop and get his fur to regrow.

Have you tried any calming remedies--calming treats, or collars, or Feliway diffusers or sprays?

I have a diffuser but have not tried any treats. Since I posted this, I noticed he is being more interactive and not so focused on himself. Maybe the vet was right and He just needed time to one to grips that he almost died and made it through. I just hate that he is anxious. Thank you for the tips. I will try about anything that will bring him some relief.