Respiratory ifection Not sure what to do next.

I have a mixed flock of chickens and ducks. I have raised them all from chicks. the free range all day in a huge fenced area. I took 15 different birds to my county fair and I came home and a day later I noticed this gurgling noise coming from one of my orpington hens every time she took a breath. I scooped her up right away and put her in a crate with antibiotics for respiratory infection. I checked over the rest of my flock and everyone else was looking fine. later on the same day my other orpington hen randomly developed a bubbly eye and one side of her face is puffy. I confined her also , next I notice my EE hen is laying in corner opening and closing her eyes. I confined her too. then this morning I notice my Wyandotte hens eye is puffy too. they have been on antibiotic that's mixed in with there drinking water. twice a day I am sucking up water in a infant medicine dropper thing and giving them the antibiotic water directly to make sure they are drinking it. I am using 1teapoon for 1 gallon. By the end of today they were doing even worse. my orpington hen is making this squealing noise when she breathes on top of the gurgling. and my EE hen has snot running out her nose. I also noticed one of my ducks had a slight cough. my whole flock is being medicated including the ducks.

I have never had a disease or illness in my flock before. I am scared i am going to lose my flock. I already lost my dog and a couple days after that I lost all but 6 of my batch of 40 quail to coccidious. which I have my last 6 survivors on corid in their water. and now my big flock is infected with this crap and im praying that some of them will make it trough the night.

How long does it usually take for this illness to do its thing? the medicine bottle says use for 5 to 7 days. what if this keeps getting worse or doesn't go away in 5 days? I don't have a vet anywhere near me that will look at chickens.

what can I do to help the swelling of there faces and their bubbling eyes?

and is their anything else I can give them or do for them on top of the medicating with antibiotics to make this heal up faster, or to stop it from spreading further?

Thanks

It sounds like you are dealing with MG or coryza. Do you notice a bad odor around the heads of the sick ones which can be common with coryza? Both diseases can have nasal drainage, and swelling of the eyes. Both can be treated with Tylan 50 injections, but coryza can also be treated with sulfadimethoxine as well as sulmet. These are contagious, and will make carriers of the flock. I would separate the sick ones for treatment. Think abbout getting it tested.