Re: Mononucleosis questions
Your first doctor probably didn't catch the mono because either he didn't test for it, or the test was a false negative. Maybe when you thought you had the flu, it was actually mono?
There are 2 viruses that cause mono: epstein barr (which is the one they usually assume is causing it) or cytomegalovirus (which I think requires a very specific test to diagnose), so perhaps you were misdiagnosed at first, although it sounds like you've had more than one illness..
As far as your question whether mono causes ear or sinus infections, I would guess no, since 1)it's a virus, and it sounds like they determined you had bacteria 2) The symptoms of mono include things like fatigue, swollen lymph nodes in the neck, or an enlarged spleen, but not typically sinus/ear infection. A very common symptom, though, is sore throats.
It sounds like you have had to deal with several types of infection... that must have been really unpleasant. I wish you luck in staying healthy and finding out why you keep getting sick, if things don't get better.
Great health wishes to you!