What you describe, an opacified maxillary sinus, is a potentially serious problem and will need to be addressed. Sinusitis is probably the cause of your headaches and postnasal drip, but almost certainly not the cause of your shortness of breath, except to the extent that sinus disease can be causally related to asthma worsening, and it is definitely not the cause of your "severe chest pain."
The combination of shortness of breath, especially "throughout the day" , and "severe chest pain" is worrisome and raises consideration of more serious diseases such as recurrent pulmonary emboli, also called clots to the lungs, and pulmonary hypertension, either primary or secondary to emboli. Pulmonary function tests (PFTs) could be helpful to the extent that it could rule out the diagnosis of asthma, but more to the suspicion of other disease would be an echocardiogram, a D-dimer determination and a CT scan of your lungs to rule-out pulmonary emboli and diffuse interstitial lung disease (ILD) that might not be apparent on plain chest x-rays.
You may well benefit from sinus surgery, but before agreeing to it, you should ask the ENT for his/her opinion of the significance of an opacified sinus, the procedure he/she recommends and the likely outcome of the surgery, such as benefits and untoward results. If you are at all reluctant to proceed with major sinus surgery, you should request a second ENT opinion. More importantly, you should proceed with further evaluation of your chest/lung problem, before scheduling the sinus surgery. As a first step you should discuss this recommendation with the pulmonologist, in whom you have the most faith, and share this response with him.
You should not delay arranging for further evaluation.
But I am going to get another CT of my chest before the surgery. And in your opinion, is the endoscopic surgery for the sinus' reliable? My ENT thought it was quite necessary since it didn't go away after being on antibiotics for a month. I was referred to this ENT from a different ENT doctor. I'm actually starting to use a neti pot and it seems to be helping a little bit when I'm not congested enough to use it. Thanks Doctor.
I have a friend who has opted out for sinus surgery. She has had many sinus bouts but feels the odds that it will really help are not favorable. She is working with other remedys for the present. Is it really necessary after only one serious sinus infection? Think about that.