Chronic Sinus Congestion

I have chronic sinus infections.  For the past 10 years I have had allergies and been on Zyrtec to treet them.  Over the past several years I have had chronic sinus infections.  I always feel congested.  I have gone to the doctor and been told to continue taking decongestion medicine and nose sprays.  I have done all this and still feel congested all the time.  Sometimes the congestion leads to sore throat and ear ringing and stuffiness.

Should I see an ENT?  Is my allergy medicine causing this?