I think I am experiencing the same thing. Beginning in January, I was weaning myself off of 40 mg of Nexium 2x per day (plus Zantac) and over 2 months I was able to get down to 20mg of Nexium 1x per day. Then in April, I traveled overseas, caught a virus, and my GERD has been unbearable 24/7 since. I am back on Nexium 40mg 2x per day and Zantac and Gaviscon -- but it is not working. I have been told by doctors that I have failed drug therapy and need to be considered for surgery. I was also diagnosed with Barret's esophagus. I am working with a nutritionist and am on a careful cleansing diet and homeopathic remedies. I just started this week and so I don't have too much to report except that if I follow the diet carefully, I do feel better (not normal or good, but better). I understand how mentally this wears on you. I have been feeling very depressed about it. Even water gives me terrible reflux with chest pain, throat burn, even burning in my nasal passages. I never imagined it could be this bad.
I would recommend that you see a nutritionist and watch your diet very carefully until you feel better. I am optomistic that diet and some alternative therapies like acupuncture and homeopathy can make a difference.