I think you are doing the right thing for you. I love love love my chickens too, but I may draw the line at a different point. It's a personal thing. Each person has a point where they say "enough". But every person makes the decision when they're ready.
We put a very old dog down a month...
I ordered several times from Twincitiespoultrysupply and they always sent this 2 page guide to medications, dose, illness, etc. I think the 2 meds that have worked the best for me is sulfadimethoxine, which works for cocci and enteritis. It's got an antibacterial action as well which is good...