Sorry to hear your not feeling great. Ok so the positive is that 14 months post op your new stomach pouch is healing good style at this point and to date you don’t seem to of had any issues. Like you say just be mindful of the manor in which you eat making sure you apply the 20+ rule at all times and really don’t push the ‘I’m satisfied’ boundaries with your portions.
Another thing could be stress.?? lots of people feel stress in the stomach area, it’s a crazy time at present so this may of just caused some irritation to the stomach?? I would be inclined to advise that you go back to fluids for a few days (good nutritional soups/shakes etc) and allow the stomach to settle… observe and see does this help with the symptoms you are having. Have you spoke to your dietitian lately.??
It may be worth a call to your surgery to discuss also especially if your symptoms have worsened overnight
Hope this helps and look after you, let us know how your getting on xx