How much PPI do you take?
After having a stable situation with a PPI I had a flareup, which I think was caused by lifting very heavy boxes. So, if it's not that you have some other problem, do you have any idea what happened when the flareup started? A stressful situation? Stress or physical pressure on your diaphragm can exacerbate (best to stretch, don't slouch, relaxation...) Another possibility might be to adjust the meds you take. I needed to add Pepcid/famotidine in the evening. I did the 24 hr ph monitor without getting off the PPI - getting off it quickly might make your situation further worse. I'm working on gradually replacing my PPI in the AM to pepcid. Maybe a different medication might also work better for you. Hang in there!