My (13F) parents don't believe me and say that I don't have a problem. My mom always chews with her mouth open and does lip-smacks before like every other scentence. My dad constantly cleares his throat and sometimes cracks food with mouth open. My big sister, though, has misophonia as well. 
Our parents refuse to believe tat mental illnesses and diseases exist and say that I spend too much time on the internet so I started believing in a lot of unreal stuff and thinking that I have all of those. 
Yesterday, I imitated mom's lip smack to feel better, as I do. She started yelling at me saying stuff like "You could've ended up with a fat ass mother that burps and slurps and chewes with her mouth open, but you have me! When you move out and see those people, you will want to have KISSED me!" and so on. I had no words and just started crying like crazy. I've never cried that much in my whole small life. I thought at least my dad would try to comfort me, but instead he started saying things like "You have to learn how to control yourself better. If it was my mom, I'd just ignore it. I've been with your mom for x years and I've never heard anything abnormal. You'll go to the volleyball camp, science camp, then college and there will be people farting and blah blah blah. Controll yourself a bit! Appreciate your mother!"
Then, my mom started saying it's because I don't go outside enough. Like, that's the dumbest thing I've heard in a while. After that, she started saying what she hates about me, like I didn't make my bed that morning (I had school, for the record) and she is 1000x more annoyed by my messy room than I am by the sounds. HOW WOULD YOU KNOW THAT, HUH? They think it's easy to control it like anything else. 
I started screaming and crying of not knowing what to say anymore. They even thought they were kind explaining this to me. Then, I got some "Stop crying! There's no reason to always cry!" Then, I cried for around two more hours in my bed trying to sleep, and with them having the door open and the TV playing. My sister probably couldn't sleep because of my screaming/crying combination. I heard her crying as well, she heard the whole conversation. 
Then, my mom walks in, ruins all the clothes I've folded and tells me to sleep on the balcony if I'm going to do it so loudly. I just screamed even more. She just randomly hugged me to the point of no breathing 20 minutes later and said: "I can go out of the house or die now, but I'm not doing it for you. This is my house and we are all going to eat together from tomorrow morning". I didn't want anything else! Just a bit of understanding and love. 
I woke up at 6am even though I cried until 4am and I couldn't sleep. They started behaving like nothing happened and didn't even apologize. I wasn't hungry the whole day and when I ate a cup of soup at 5pm (my first real meal) I've almost thrown up. Probably because of what happened yesterday. I still feel sich though. I won't be eating anything today, then. We'll see about tomorrow. 
What should I do? I know this is just a temporary peace moment…
Sorry for the typos, my eyes are full of tears just writing this. Thank you for reading this far! We'll get through this. :D &lt;3