Honestly, and this can be hard when you’re 16, I know, but you may have to find a way to politely excuse yourself from the situation. Find a reason to walk away, use the restroom, grab something from across the room, etc.
Also, it may be best NOT to share this information with most others. It’s nothing to be ashamed of, of course, but phobias aren’t taken terribly seriously by many, mostly because I think they don’t relate. And, your peers especially, will want to tease you. Misophonia is one of those quirks some of us have that WE need to adjust our lives around, not others. Our triggers are valid, but it’s not acceptable that we expect people to change their eating habits.
Also, check out DBT, especially the mindfulness module. This has gotten me through so much.
Don’t worry, you got this!!