Bangers, I understand exactly what you mean. Any
situation that cuts me off from bathroom access
can cause great anxiety, in case I "might" have to
go. Of course the anxiety can quickly become acute
enough that I do indeed need to go. Immodium in
advance of these situations is helpful, and
relatively gentle to come off.
I've tried phoning ahead to some places I have to
go to ask about their facilities and/or procedures
so I understand what I'll be facing. If I have time, I
might try a dry run to some new place, just to get
familiar with the territory. It's a drag when you feel
you can't trust your body. If these physical
symptoms team up with a real mental panic, well,
there's nothing you can do at that point in my
experience. Breathing, focus, etc. are all the tools I
have. Also, when venturing into new scenarios,
visualize "worst case" scenarios in advance and if
you follow the steps logically, you may find the
worst case isn't really so bad, and you can reduce
your anticipatory anxiety.