I don't know if it's right or wrong, but I think you should try to understand them. To people other than us it seems strange that noises make us feel the way we do. It's not a disability that you can see and know that it exists and sometimes people think that we are exaggerating or "putting on a show" to get attention. You have to explain to everyone that this is a real thing and that you don't want it just as much as they don't.

Whether its normal or not i’m unsure, but its definitely not very supportive or productive, but unfortunately thats often the way people will respond to behaviours they don’t understand. So explaining how misophonia affects you may help in some cases if its just a matter of misunderstanding. If there are still some who don’t understand and laugh, i don’t think its worth investing anymore into that relationship (although i realise its not always easy or possible to just cut toxic people out, but where possible i think its for the best)