Smalltown80sBoy & traveler, covered things pretty well.
I'd add...

If u have a Therapist, discuss this with them.

If you are on medication, bring them & perhaps see the psychriatrist b4 u go also.

Practice a "grounding excercize" b4 u go. So u can calm yourself b4 entering stressfull encounters.

Don't bring weapons with you. Not even a pocket knife. If u need that to feel safe, you shouldn't be going in the first place.

Bring something with you that is comforting. It could be a picture, or a small item that reminds u of a happy experience, or even a piece of clothing. When u are stressed, concentrating on the item will help reduce that stress, especilly when used with the other methods offered in this thread.