I am sorry to hear that those you felt closest to have passed. I hear you and there is absolutely no pressure to leave home either. Absolutely, if you do not feel 100% safe around your friend’s brother, then it’s not an option to pursue.
I think one of the major ones (that may not change the situation with parentals, but can help how you deal with it inside) would be to recognize that it’s not your fault. Sometimes my parents will blame me for things because I’m right there. It’s not fair, and it’s not right, and it definitely means they have their own issues, but please remember to remind yourself that they’re taking it out on you, just because you’re there. You didn’t do anything wrong, and you deserve to be treated with respect.
I also believe that it kind of helps to tell yourself it’s okay to take up space in your house. You are allowed to take up space, speak up for yourself (if you’re comfortable with that), allowed to feel, allowed to voice your opinions. Of course, those tips don’t necessarily change the immediate treatment of you by the parents, but at least, they may recognize that you’re silently standing up for yourself.
I’ve stopped trying to analyze what their thinking, whether it may be about me or not. I’ve also had to learn and not read into some of the things they say; they’re human, they say things, and sometimes I think they’re so wrapped up in their own lives and worlds that they may not see that something said impacts their kid.
Staying productive with hobbies and things that make me happy have also helped, and my parents are respectful of things I’m passionate about, and even encourage it (e.g. photography, working out). In turn, these hobbies. get me out of the house more, and away from home when it’s mentally too strenuous. I throw on a mask and go out to take pictures with friends or alone- that’s been nice.
Oh, one last thing: if it is at all possible/available/affordable, I encourage you to seek the help of a professional/therapist. I’ve honestly gotten most of these ideas from my therapist and about how to cope at home. If it is something you’re comfortable with, I very much encourage this option!
I apologize this is so long, but these are just small things I’ve learned along the way. Please let me know your thoughts, and maybe we can pool some ideas together as well. You are not alone. Not now, not ever.