Damp substrate will not cause respiratory problems unless it gets cool. How are you measuring your temps? Where in the enclosure is the thermometer? Is it an open topped enclosure? What are you using for night heat?
I have the zoo med thermometer sticky strips right at substrate level, and i also have the two in one thermometer/ hydrometer as well, it is an open top, and using the 100wt red light for heat day&night with thermostat to keep heat adjusted and he gets natural sun just about every day for atleast 30-60 min.
Update- Mac seems to be doing a little better today. He is not doing push ups any more and not blowing bubbles. We will stop go to our vet appt on Monday but for now he is doing ok. Thank you all for your help and support.