Please do not take this personally. I am sure everyone and their grandmother has phoned in with an illness. Unfortunately, this has also been abused and the reaction has been cancelation fees. I know you were trying to be proactive, and this infection sounds miserable :-(.
Also, think of all the equipment that is needed for your procedure, if he had to order it, and the proper care of that equipment. This is not something you want skimped on to save costs. Think of the dentist that was caught not sterilizing his equipment and exposed many to HIV.
It might be time for you and this dentist to part ways. I go to a dentist that is two towns away. I pay out of network fees, actually my whole family does, to see him. He has reasonable fees and keeps his cost low for his patients because he manages his practice so well.
He is starting to plan his retirement. It is already freaking me out. He knows I plan to move where he retires, and find him on the golf coarse if needed ( I have dental anxiety, not a stalker, he is aware of that too, LOL)
I would not feel comfortable with someone working on my mouth, especially when I need a lot of work done, who I didn't trust. It is not good for either of you.
If you want to continue to use this dentist, reschedule and then let this issue go. Sickness happens. This is really the only way he can protect himself, and leave it at that.
Otherwise it might be time to move on.
I hope you feel better soon :-).