Toxic Family

I'm sorry, I don't know if this is the right place to write this, I just want to get some advice. I'm a 20-year-old with two brothers who grew up in a toxic family, and I want to fix my family before I leave and start my own life. Believe me, I don't feel like leaving my little brother like that. My second brother ruined his sports career for an unpleasant reason. Of course, his education life ended because he left school for sports. Also, we haven't been able to get along for years and now I'm literally being mobbed for reasons like I can't beat him anymore because I made him cry once when I was little. Even the sound of my spoon touching my plate while eating makes him angry. He hasn't left the house for about 6 months and can't go out because of his paranoia that he will get into a fight. I'm afraid that if I leave home, he will fight with my father and do something wrong. As for me, because my family makes me tired, 
While I'm working, I don't pay much attention to my family due to reasons such as preparing for university and my own pursuits. My parents are a little older, I can only say that they are more understanding.
This is the picture, it's probably not much different from an average family, but I'm really not overly excited about living like an average teenager, and I don't want to leave my family like this when I've devoted my only goal to something as simple as starting my own family. Can a toxic family get better? What is the way to do this? Is my family a hopeless case? I'm sorry if I caused you trouble. And I'm really sorry for my bad and translate english.