My cat is not eating due to sickness

My cat has a bad lung virus or something because he has been coughing up green mucus, he will not eat and has drank very little water. He's feral so he's never had any shots, I called a local Vet and they said they would have to do a test ($48.00) that I can't afford, just to see the Vet costs $38.00. I don't think that there is a Veterinarian school in my area either. The Vet I usually take him to is retired and does everything for much, much less but he's on vacation until Monday, I had taken him there for the same problem a month ago and he gave him a shot and a bottle of ClinDrops that I have been giving him twice a day which I think is the only thing that's keeping him going. Do you think antibiotics from amazon would work? Any suggestions PLEASE? I'm desperate because I love this little guy.....

He really needs to go to a vet, but you  also need to get nutrition in him if he is not eating. He will develop fatty liver if he does not eat. Here is a thread on syringe feeding (http://www.thecatsite.com/t/227858/syringe-feeding-lucky-video-if-your-cat-is-not-eating). 

Some people find putting their cat in the bathroom while you run a hot shower helps with mucus. 

Is there anyway you can borrow the $38 or get credit care to take him to the vet? On a side note I know money is tight but $38 is pretty reasonable for a vet visit- where I live it is almost impossible to find a vet who charges less than $100 for a visit!