I suggest that you go back to see your primary care doctor
. It sounds like you have seen too many specialists, and at this point you are getting a lot of tests done that are probably not necessary or are difficult to interpret. Your primary care doctor, as the doctor who knows you best, can probably take a fresh look at all of the tests you have had done and the symptoms you are experiencing and can see if there is an obvious pattern or plan of attack.
If you are dealing with sinus infections or chronic allergy problems then this is something that your primary care doctor will be able to help you deal with. There are no specific symptoms of a sphenoid sinus infection (as opposed to other sinus infections), and all sinus infections or sinus congestion are treated basically the same, something your primary care doctor can help you with.
I also think the positive ANA titer should be followed up. It is positive in the borderline region where it is hard to know what to make of it, but additional blood tests to look for inflammation may be indicated. Your primary care doctor may do this, or may want to refer you back again to rheumatology.