WELL digestion issues are my specialty.
My BFF are these supplements.
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I know they're a bit expensive but you can also try Digest; it just has lesser amounts of the same ingredients. You might be having issues digesting food properly and these supplements help you digest food.
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These are drops I do when I'm having indigestion issues. Calms my stomach down within 5 minutes.
Now, these are only for physical ailments. I'd suggest looking into some sort of therapy or breathing exercises before you get into social situations. If I know I'm going into awk situations, I give myself a quick shoulder massage and then end it with deep breathing. Breathe from your stomach; in through your out through your mouth.