Dry Throat

Hello,  I
for the last 5 months i"ve been sick with a some type of throat infection at least twice a month . it started with a cold that turned into mild bronchitis followed by a nasty cough that lasted almost three weeks. I got another mild cold that only lasted about a week and a half following that i got my first real obvious sinus infection. I had swelling on the top of my head right above my forehead. the swelling lasted about 3 days and I had a headache on the same part of my head which was on my left side of the lower part of the back of my head and pain behind my eye. for about a week and a half. finally that went away 2 days after that I got another cold . I had a lot of congestion and stuffiness. that lasted 2 weeks. 2 days after that i got a sore throat that lasted 4 days.  I've gone to the doctor and told them all this . i was given penicillin for my sore throat this last one and Loratadine.  The doctor told me I might have allergies and the nasal drip was causing irritation in my throat. It has been a week since then. now i'm experiencing dryness in my throat and a few  days ago I started feeling dry throat sometimes but it would go away but now my throat is really dry and it bothers for 3 days now. It makes my voice kind of hoarse.. I've never been sick this much this often in my life.  i'm starting to get concerned that i might have a more serious problem . what should I do? please help