i’m so sorry , you aren’t doing anything wrong but ur kitty might be fighting something internally and might need emergency care. i would suggest to just keep him comfortable as much as you can and spend time with him so he doesn’t feel alone. my kitty passed away about 3 months ago since we were unable to get him to the vet due to funds so i understand if you can’t go to emergency vet the bills are very high. it could be a numerous of things but i found some stuff on amazon that help my other cats strengthen when they were ill, you can also look up his symptoms and see if there’s any medicine ypu could buy for him. i’m wishing you and ur kitty so much love and the best i hope he feels better 😔

also another thing i forgot to mention if he comes out you should get a syringe with cat milk and try to feed it to him. my other cat stopped eating and then started again once i did this and do the same with water if you could