You are not a bad person. Not being able to create or sustain peaceful life will never mean you are a bad person. In fact, wanting a peaceful life for you and your family makes you a GOOD person!
You are not the only adult in the home. You do not have to make the environment perfect for everyone. If you try, you’re going to fail. Not because you are incapable of achieving a peaceful environment, but because a perfect environment cannot exist if EVERYONE in that environment works for it.
Consider a different perspective - Don’t think of your situation as a family living in a house. Imagine it as a communal living (like a dorm or apartment complex). You each have your own space (bedroom) where you’re free to be yourself - YOU are only “solely” responsible control of THAT space, because it is YOUR space. So, if your room is messy or unorganized and your siblings get upset because they like it clean, then tell them they can clean it. If they say it’s not there mess, say that’s true but it’s also not their space. Would they go into someone else’s house and tell that person its messy and that makes them upset, or do they respect that they are not responsible for another person’s space?
Communal areas, like living room, bathroom, kitchen, etc are not YOUR sole responsibility. Everyone getting along is not YOUR sole responsibility. They need to be as considerate as you have been, and put in the work just as you have been doing. If you try to pick up their slack, you’re going to get burnt out.
It’s okay to just be there for a roof to be over your head. It does not mean you are required to play house. You’re not responsible for their happiness, but you are responsible for your own.
Im proud of you for being open and reaching out when you are struggling. Whatever you decide to do, don’t forget that you do not owe them anything just because you’re related. They are fortunate enough to have you as a sibling :)