I have to say I've been in your situation, and recently. By what you write here you seem to be doing all the right things. It does get frustrating when you know you need to do something, but you can't get in to see your doctor. Ideally, your doctor should see you right away so you don't get into further trouble. So the only thing you can do right now, that I can think of, is to continue to do what you've been doing, and continue to monitor your peak flows. If you continue to see a drop in your peak flow rate that isn't improved when you take your rescue medicine, then you may have to result to the emergency room. Other than that I know it's frustrating, but you'll just have to hang in their until Monday.
I've been on Advair, I feel like it makes me worse more so than better though. And I don't have a neb at home, I don't think I'm bad enough to need one. I made it into the doctor that week and was given Predinsone. It helped a lot. I'm back to normal. :) Thank you!