I am anxious. This horrible feeling of constriction and being closed in is a very real part of being worried and anxious.
I make an effort to stand taller, breathe deeper. The physical change helps my mental state, a little. Like the fight to breathe deeply, the fight to push worry aside is an ongoing, breath-by-breath effort.
"Do not be anxious about anything. Instead of worrying, pray... And... Jesus... will come and settle you down..." That's a mix of NIV and Message versions, I think, of a scripture I once knew better, in Phillipians. Time to learn it again, it seems. Watch this space!