In The Last Three Weeks I Have Developed Chronic Heartburn.

In the last three weeks I have developed chronic heartburn. It is the worst late at night and in the morning. I have had a endoscopy, and the gasto said I have been suffering from acid reflux for awhile. However, it has been only recently that I have had these severe heartburn episodes. I have been taking Prilosec for the last two weeks which seems to take the edge off, but I still have them. Also not eating after 5pm and sleeping more upright helps. The gastro said I need to stay on the Prilosec for 8 weeks. Any other ideas?