My son had pretty bad reflux, we never tried peppermint or chamomile, but there were a few other things that helped. Gripe water helped sometimes, they have it at health food stores and Kroger. Mylicon also helped sometimes. He was never able to breast feed, so he had formula. I read several places that the process they use to isolate the DHA in baby formula adds a chemical that bother baby's tummy, so when we switched to Nestles Good Start Supreme without DHA (the purple label) it helped A LOT!!! We can add fish oil to give the oils they need, without the harmful chemicals.
Another trick is this: Hold baby on your lap facing out (back of baby's head on your chest) rub your hands firmly one after the other from the bottom of baby's ribcage to top of diaper for a count of 15. Then bend baby's legs up toward their tummy, hold for a count of 15. Then rub, in a clockwise circle, baby's tummy for a count of fifteen. Bend baby's legs to their tummy again, hold for 15. Repeat process until baby calms down. It usually doesn't take very long. It helps to count out loud in a soothing tone.
Hope this helps.
My heart goes out to you for the loss of your little boy.