We had a lesser version of what you described at our house when I was growing up. The response to me whenever I was upset about anything was a patronizing, "don't be so melodramatic" and then no validation or problem-solving ever occurred. Or if my brother and I fought they'd just separate us instead of problem-solving, and my brother and I still can't stand each other to this day (we're in our 40's). I think a lot of people think parenting is going to be this lovely magical thing and then when inevitable sibling spats happen, the parents refuse to acknowledge it or use it as a teaching moment because they have no idea how to do those things. It's all just a big annoyance and that magical view of parenthood turns into stone cold cynicism.

Anyway, I really like HusleysParadox's suggestion: "I have an idea.. What if you took a summer class in something you enjoy doing? You don't have to talk to anyone in the class even try to make friends, but find an interest outside the house and don't tell your family about it. You're an adult right? If they ask then say "I'm going to do my thing."

Truly brilliant. If there are no sensible boundaries at home, then create your own outside of home and focus on that as much as you can while tuning out the home situation as much as you can. One thing about that - my mom found respite in learning to do things her overbearing parents knew nothing about, so that they couldn't try to control what she was doing and they couldn't criticize her. She learned to sew and play violin, two things they knew absolutely nothing about, and they were great escapes for her. I've recently started beekeeping, and am having a similar experience. Other people are interested but can't tell me what to do or criticize me because they know even less about it that I do (which isn't much yet, I'll admit). Is there anything that interests you that they know absolutely nothing about? Choosing something like that is another way to distance yourself from the craziness at home.

Good luck. I hope you find effective ways to cope with all of the frustration, which is putting it mildly from the sound of it. I hope you find your own respite and are able to tune out all of the negativity.