Gerd can bring us symptoms even while taking meds. You have to still watch your food and drink intake. Your test for Ulcers were negative so that should give you some comfort that an ulcer isn't causing the pain you felt. Stay away from refined sugar, tomatoe products, and spicy foods. Watch to see how well you digest dairy products too, because all of the things can exacerbate symptoms in some of us sufferers. Also, look at the ingredients in the tea you're now drinking.
Living with GERD for many of us is a life long battle of discovering what we can and can't eat comfortably. It's also been mentioned that high carb intake bothers many of us. Hope this helps.....