Re: Sinus problems please help!
The two most common causes of post nasal drip are allergies and acid reflux (particularly a type of acid reflux called LPR that irritates the lining of the esophagus).
Because you don't have insurance, your best bet would be to try taking an antihistamine daily for two weeks to see if your symptoms improve (in which case allergies are the most likely cause of your symptoms). You have lots of options but generic Cetirizine (Zyrtec) is a good choice. It's relatively inexpensive, shouldn't make you tired, works for 24 hours at a time and you don't need a prescription (loratadine is also an option but isn't quite as strong). Just take one of them every day for 2 weeks to see if your symptoms improve.
If they don't improve, you may want to consider a 4-week course of loratadine (PrilosecOTC) to see if LPR could be causing your symptoms (particularly if you occasionally have heartburn, which is not always a symptom of LPR but is a good indicator that you have reflux issues).