Pneumonia - post antibiotics and recover, what's it like for an elderly person?

We took my 86 y.o. dad to the ER about a week ago because of a fever and listlessness. In a CT scan they discovered pneumonia in both lungs. A few days later the culture showed a klebsiella bacteria and also candida albicans and glabrata. He is on amox/clav and Diflucan. Although the docs wanted him to stay in the hospital, we brought him home. He's still listless and not eating and now has phlegm. We wonder are people still plegmy and coughing even after 3-4 days of antibiotics? He has anemia also, so this is probably really taking it out on him. We are not sure he can recover. Would like to hear others experiences with pneumonia. We don't mind providing him with "hospice" care or just supportive care with fluids if we are on that road. It's scary seeing him so zonked out in bed. A week ago he was able to get around the house. If it just takes a long time to recover then we can also persevere. Not knowing is tough.