I am sorry to hear you are worried about Barkley. My name is Rebecca. I am a veterinarian and will do my best to help.
I agree that you should be worried; eye infections can turn serious. The best treatment for an eye infection is a good examination of the eye, and usually topical antibiotic eye ointment. There are ways to get help with vet bills; these websites lists some:
Vetbilling.com is a site that can let you make payments; you don't need a credit check, just a checking account.
You can get Terramycin over the counter and online (unless you are in California); it is a topical antibiotic eye ointment. You can gently clean the eye, and apply warm compresses to remove the discharge.
There is a condition called dry eye, where there is a lot of mucus in one or both eyes. There is a reduction in production of clear tears, so the mucus glands around the eye overproduce mucus, which can look like pus. This condition does require prescription medication. You can use artificial tear ointment frequently as part of the treatment, and you can get that over the counter.
Let me know if this is helpful, and what other questions I can answer.