I am also 17, and I don’t remember a specific time when I noticed my misophonia but I know it started to get really bad last year. My biggest trigger is lip smacking. I am also triggered by shushing, certain consonant sounds/pronunciations/speech patterns, and doors slamming. They send me into a blind rage and sometimes make me panic and hyperventilate. Last year I had a history teacher who smacked his lips loudly and wetly pretty much every other word, and a lot of his speech patterns and pronunciations were triggers for me. Sometimes in response to these triggers I would quietly mock or even hit my desk. Eventually I switched to less disruptive coping mechanisms such as digging my nails into my palm, which isn’t a great strategy but works because the mild pain distracts me. Towards the end of the year he triggered me so much that I had to put in headphones during his class every day and drown it out with loud music. I ended up having to teach myself most of a unit because I couldn’t cope with my misophonia.
My parents don’t know I have misophonia and I didn’t tell them about my problems in class. My two best friends know and are very understanding, and I also have one teacher who knows. I told him about my trigger sounds and he helped me figure out some coping strategies for class/social situations.
The best thing you can do, besides trying to avoid your triggers when possible, is talk to someone you trust and find some strategies to calm you down when your misophonia is triggered. I am in no way in a position of expertise as I frequently struggle with misophonia and have told very few people about it, but there are some things I’ve found that help. Find a simple movement that you can do habitually when you are triggered to stop yourself from responding with anger or panic. For example, press your hands together, clench your toes, or flex your arms when you are triggered. Having an automatic response helps to pull you away from the anger you feel when you hear a sound trigger. (Try to avoid hurting yourself in response to a trigger in order to keep a reaction inside. I have a bad habit of digging my nails really hard into my hand when I’m repeatedly triggered.) Headphones are always the preferred way to block out triggers, but when they aren’t an option, you could try deep/paced breathing and counting or reciting something in your head.
When it gets to be too much, get yourself out of the situation. My preferred excuse is to go to the bathroom. Sometimes, when I was having a bad episode in history class, I would ask to go to the bathroom and then take a walk around the school while getting control of my breathing. At home, I sometimes go upstairs and lock myself in my room for a few minutes or get a drink of water (always helpful). If you’re feeling like you might explode, try finding a private place and screaming into a pillow or hitting something soft, like a stuffed animal. This sounds silly, but it does help. Generally, I find that running helps me deal with anxiety and stress, so regular exercise should help take the edge off of misophonia responses.