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The exact same thing happened to me. When this whole experience first started for me, reflux would only hit on random occurrences - sometimes I'd eat pizza and be fine, sometimes I'd be up all night. Once I started the Nexium and started avoiding those foods, EVERY SINGLE TIME I'd eat them after that would result in a reflux episode. My GERD is now under control with 40mg Nexium per day and a vegan diet (still avoiding triggers). But even now, if I eat something bad (like soy sauce), I can feel a lot of bloating in my stomach. Fortunately, it's MUCH less painful than before.
I also tried to go off of my Nexium once and lasted about 13 days before I went back. The rebound is just terrible. They (Astra-Zeneca and doctors) don't really make that well-known. I feel for you :(
I agree with the very wise Bill in that sometimes eating something doesn't help, which is really unfortunate. I've found that Gaviscon helps quite a bit in those moments, especially if it's happening before bed, because then you're eating right before laying down which has always been a huge trigger for me.
If it's possible, you may want to go back to your doctor and try to get his help in weaning you off of the Nexium. Let us know how it goes!
Best of luck to you!