"If I have baa-chan"
Well, someday you won't have her, and not just her. One day, your parents will die, and your brothers or sisters will have their own family to worry about. Your friends may also betray you and stab you in the back. Your lovers, at some point they will leave you, either to die or to cheat on you and divorce you. Your kids will also leave you when they grow up, and same with your siblings, they'll have their own families to worry about, more than they worry about you.
Face it, each and every one of us is alone. We have no one else to rely on except our own selves and God (if you believe in God). So, you'll have to stand on your own feet, whether you want it or not, because at one point, no one will be there for you, and help will never arrive, at least not when you need it the most.
You are your own responsibility, not anyone else's.