I'm too nice externally when I genuinely don't give a fuck inside

I genuinely do not give a fuck about any of the people in my daily life but I talk to them so nicely. I change my way of speaking, my way of humour, and all that just to talk to them.

This is one of the reasons why I have so many friends at my school. From backbenchers, to overachievers.

But I hate it just as much as I love it. I like the fact that I have so many people. But I hate the fact I have so many people to the point I have to help them so much.

I stopped giving them work, advice and time online though. It kind of ruined my social life because I'm getting less attention and my friend is taking it all, but the good thing is she's very anonymous in her general life so no one really knows her. (Yes, I'm jealous)

Another thing, this same friend is such a copycat. If I say something, she'll say it to someone else. If I tell a joke, she'll say it louder. If I become social, she'll too. If I get many friends, she'll too. If I become quiet, she'll too. I fucking hate her.

Just give me advice on anything so relevant if you can.