Anyone get sinusitis/bronchitis back to back?

Every winter I get a sinus infection and bronchitis, take an antibiotic, it goes away for maybe a month, then comes back again and I have to get an antibiotic again. It really frustrates me. It's only November, and I'm already on my second sinus infection. I don't want to get an antibiotic again because I just took one a month ago. Anyone have any suggestions? I've tried everything too. I've read all about natural rememdies, and tried them all. I wish I could figure out how to strengthen my immune system so I don't keep getting sick.

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