Social events can be a big struggle. The first thing is to wear ear plugs. Hopefully, they will lessen the audio stimulation to a level that you can tolerate for a while. Bright or flashing lights just need to be avoided. And, always have an escape route to a safe place.

And, be ready with a memorized explanation. "I suffered a brain injury a few months ago and my brain does not process the lights and sounds properly. The lights and sounds have given me a horrible head ache."

This is not something you can push through. I bet you will fell lousy for a few days.

My best to you.