If my vet (and she's an excellent one) is confronted with eye issues that just don't get better, she usually refers the client to an ophthalmologist ( a specialty eyedoctor), because timely treatment is just so crucial.
I know that money is an issue. Is Carecredit available to you?

https://www.carecredit.com/

You can use a steam cleaner for the scratch post. Or use carpet shampoo and then let it dry in the sun. Exposing it to sunlight also kills bacteria.