Is a nasal infection that last 1-2 weeks consider chronic sinusitis? happens 2-3x a year with cough & sore throat. normal cold or see ent? cystic fib?

Infrequent nasal inf: The pattern does not appear consistent with chronic sinusitis. It does seem that your allergies may be relevant. Perhaps your nasal passages remain thickened because of allergies and your sinus drainage passages may also remain narrower that usual due to thick mucosal lining. ENT evaluation can be definitive, but does not seem compelling.

Possibly: Yes if you have these symptoms it could be chronic sinusitis.Somtimes if sinusitis is not adequately treated it may recur.Have you had 2-6 weeks of antibiotics plus steroid nasal spray?Have sinus X-rays been done?ENT consult is a good idea.If that is checked out then I would consider other diagnoses.With cystic fibrosis there is usually a pulmonary and/or gastrointestinal component too.