I feel like something is wrong with me mentally

I’m not sure why, but sometimes I get ‘cringed’ around my family or anyone for that matter, when they might do something.
I just get this feeling of disgust.
Also I go through waves. sometimes I want to spend time with people and other times I really don’t want to spend time with people. I never used to think I was an ‘introvert’ as some people call it. I love dancing in clubs so much, and sometimes people do consider me loud (even if I don’t have a drink).
It’s just I get really emotional because I’m currently on summer, and my family always say that they rarely see me. I’m always in my room pretty much, maybe watching a TV show or doing revision. I don’t even leave the house because I have strict parents. I would go and sit with my family but they bore me.
i always used to think that the reason why parties and family events bore me is because I’ve never had cousins my age.
However, yesterday my cousin from India came over. She’s exactly the same age as me and I find it so exhausting being with her. I’m unsure if it’s because she’s never been here before and she’s settling so everyone’s giving her princess treatment, but honestly I’m finding it so hard as it seems as though I have to be with her 24/7
I do have some family friends and I love them to bits!

First of all, rest assured there is nothing wrong with you mentally.

I think I myself am an ambivert, i.e. there are times when I love to be around people but other times when it's less so.

There are times when, for no apparent reason, I just hate being around everyone.

What about your cousin puts you off? Just the other day I had a cousin who I'd never met before, around my age, come over from Canada.
We really hit it off!

Maybe try not to judge your cousin and ask her some icebreakers, what is uni like there, what was school like, what have you been watching on Netflix etc.

I presume you are in an Indian family. I am too, and I think for me at least some of my extended family can be more judging than my parents, but that is a small minority - most of them are still very supportive.

It's also a universal thing especially in Indian families to treat guests like royalty, so don't take it too personally. The aunties and uncles in particular will expect you guys to suddenly become besties bc "you're family" but you still need to grow on someone and they still need to grow on you, that basic principle of human social interaction still exists no matter who with!

But please know that again there's nothing wrong with you and you don't have to do anything or talk to anyone if you're not comfortable.