I was told I do not have frontal sinuses based on a CT scan and that my maxillary ones show no blockages. However, I suffer from chronic sinus infecti?

How was the. diagnosis made??? headaches??? nasal discharge???? It is clear to me that "classic sinusitis" is a hard diagnosis to make and I would suggest an in person visit with an ENT (Ear Nose Thoat) SPECIALIST for an examination and possible treatment. If HEADACHES are your major symptom your PCP should turn to another explanation than sinus problems.
Hope this is helpful \
Dr Z.