Do i have a double infection and if so how will my doctor treat it?

It sounds to me like you might have a sinus infection, but because you have a dry cough, I wouldn't quite say you had bronchitis. Usually with bronchitis, you will have a productive cough(coughing mucus up). The best bet for a sinus infection is a short term antibiotic, taken orally. The only problem with your situation is, just because you are prone to infection doesn't necessarily mean that this is an infection. This is most likely a virus, and with a virus you just have to kind of ride it out. Antibiotics will have no effect on a viral illness, because antibiotics only help with bacteria related illnesses. I would give it about a week to a week and a half total, and if you are no better, see that doctor. Hope this helps!