I’ve been able to swallow pills both big and small for my entire life up until a few years ago. A few years ago I was swallowing a pill and choked on it. It scared me because I was home alone.
For about a year after that I avoided taking pills if I was alone or I would take them while talking on the phone.

I’ve gotten better and no longer do that but I still experience what can only be described as “last minute anxiety.”
I am calm before taking the pill. I put the pill and water in my mouth. Then right as I throw my head back, my mind just goes crazy and says “Stop, wait!” I panic and my throat closes and I usually have to take a break to try again later or I spit it out and crush up the pill.

Or sometimes I’m trying to swallow for so long then the pill dissolves and I will panic that way too.
I’d really like to get over this phobia because I’m going to be taking pills for the rest of my life and I haven’t always been afraid of it.
It’s hard to create a new thought in this model because I’ve actually choked in the past and haven’t forgotten the experience yet.