Going to a busy club night when you are not sure how it will feel can be overwhelming. Some practical things that help.

Eat properly beforehand

Low blood sugar makes everything worse. Have a proper meal an hour before doors. Pasta, rice, anything that holds for six hours.

Tell your group your exit signal

Pick a code word or a tap-on-shoulder gesture that means "I need to step outside for ten minutes". Use it early if you need to. Real friends do not make you justify it.

Have an exit plan

Know how you are getting home before you arrive. Save the Bolt address in your phone. Knowing you can leave at any point removes most of the underlying anxiety.

Permission to leave early

You do not owe anyone a full night. Leaving at 01:00 because the room got too much is a complete acceptable use of an evening. Promoters would rather have happy short visitors than miserable all-nighters.