Simkie - I hope you don't find my post response to be argumentative, I just wanted to reply and answer some of your questions and pose some of my own!
At this point, my plan is:
Feed her 2nd cut hay and see if that makes a difference in the amount she will consume - perhaps this may be an indicator of a hind gut issue in addition to some gastric ulcers that cropped up over the summer. She does have the tucked up flank and irritability near the back of her tummy (which can be hind gut issue symptoms).
Keep her on 3600 mg twice daily Ranitidine until I can get an order of pop rocks.
When the pop rocks arrive, I am going to give her 3 packets a day for 28 days.
I am also considering putting her on SmartCalm Ultra to see if taking the edge off (if it even does that for her) will maybe keep her from worrying herself into ulcers in the future.