If he is so sick and is having trouble breathing and seems to be in pain, why are you waiting to take him in? I would have taken him in immediately.
Also, if you have limited funds, maybe you should look into getting a credit card. I got a credit card for emergencies incase something ever happened to one of my animals, it has a $10,000 limit.
Sinister ~ black GSD 3.11.09
Draven ~ Dalmatian 6.30.13