Barb asked me to drop in and see if I could help you.
It will help if you can check a few things.
Look at his gums and tongue in his mouth. If they look white, blue, or gray where they are normally pink (gums can be black sometimes if so just look at the tongue) that will tell you if he is having issues with getting enough oxygen or blood supply.
If he is pale or blue then I'd suggest seeing if www.carecredit.com
will let you finance some vet care tonight. They might if you qualify.
You can also press on a pink area to see if the color comes right back like it should or not.
Some pups have problems breathing when they have anemia from severe worm infection. If he has not been tested for worms that could be the issue. Your vet can check a fresh stool sample for you tomorrow.
He could also be starting with a kennel cough infection. This is a viral disease dogs catch from other dogs as easily as we get colds. The cough sounds horrendous but its usually not a very dangerous disease.
You can read about it here to see if that sounds like it
It can often start with nasal stuffiness.
And this breed with its pushed in face can have issues with an overly long soft palate or the trachea compressing making for hard breathing.
If you have air conditioning you can see if AC will help - if you only have that in your car see if having him in the car with the AC running makes him feel better.
You will need to talk to your own regular vet tomorrow. Often a regular vet will take payments or a post dated check where an emergency clinic will not.
If you think he is feverish you can wipe his abdomen with a cool cloth.
Hope this helps you!