You shouldn’t feel selfish, these feelings are completely valid. I suggest you leave them, they’re clearly taking a toll on your mental and emotional well-being. For a little while I was in the same place, I had food and loving parents and a good home life but my friends were incredibly toxic and I couldn’t bring myself to leave them. Once I finally left them, I felt so much better as myself. And please, don’t resort to sewer side. I don’t know anything about your family but I have a feeling that they would want to help you if you told them about all this. You don’t need to take my advice through, I’m just a person on the internet, not a professional psychiatrist. I still want to help as much as I can. I hope you’re ok!
(Wow that was long)