Unless the coffee itself is no good for the original poster. Coffee is certainly acidic and is also a diuretic, the fact
that cutting back on the coffee and drinking more water made you feel better argues that you may have been
creating some chronic dehydration issues for yourself, Jyot. That does not mean coffee equals gluten.
Oh it was definitely chronic dehydration. I've never had a problem with ingesting coffee in reasonable doses.
I still have reaction symptoms (just not as intense as before), so, I'm just having straight coffee or home-made coffee for now while I get back to 100%. It certainly helped the 3 day migraine I got after thinking I was "safe" and tried a vanilla frapp. Oops.
I tried to contact the Starbucks company and, surprise surprise, they said "Sorry, we can't guarantee the safety of anything." They wouldn't/couldn't give me specifics. So, despite multiple online debates on multiple websites around the safety of the Starbucks syrups, mixed beverages, soy milk, and teas, I'm just going to assume everything is bad MINUS the drip coffee and the Americanos. Unfortunately, even with separate steamer pitchers and blenders, cross contamination is ever present.
I've already purchased my own dairy alternative creamer to keep in the break room fridge. I've also decided to be overly cautious and get designated gloves specifically for my use when washing dishes to avoid personal cross contamination (if I forget to wash my hands after work and then eat).
If nothing works, well, time to go to the doctor again.