Is it Mono?? Or just a cold/flu?

I also have horrible problems with my sinuses and also with mono. You definitely need to be seen by a doctor. With the fever, you definitely have some sort of infection going on. Tell the doctor the onset of the symptoms, the fever, how high, how long it lasted, the tiredness, etc. After taking your history they will more than like swab your throat for strep, they might take blood to test for mono as well. I take Mucinex over the counter for my sinus congestion, that can be safely taken even if you have high blood pressure. If the blood tests come back positive for the mono, unfortunately antibiotics won't help with that, it pretty much has to run it's course. It sounds like you might have more than one thing going on. The headaches and fever could just be due to an acute sinus infection. That also can cause the overall tired feelings. Your best bet is to be seen by a health care professional so that they can properly diagnose your condition and get you started on the correct medication. Hope this helps! Feel better soon.