Cat over 10 with feline aids

I was told I am better posting this here. Currently in rush but if there’s a different sub whenever I have time next week will look into it

He’s a sneezer big time plus getting sick. he has gotten skinny to where I can feel good bit of his bones. Anything at home I can do for sneezing? He is on Iams with hairballs control. more or less 24/7 access to food. vet just give him 200$ shot that may work and says that’s about it, nothing they can really do.

Note and not good one. I recently had to put down a cat with FIV+ two months ago due to complications and sky is starting to get similar. So far he hasn’t had much breathing problems but once he parks he stays parked