"am i a bad sister?"

i started my morning yelling at my brother on the phone, and i realized that they already been exploiting my kindness to them, i can't stand them anymore i've been a good sister but there's always an end to all of this. i felt like i have given all the remaining of me to them, and they took the opportunity, i hope they will learned their fault, it's not that im being selfish but i have to think about my future. i still feel down until this moment and somehow i am planning to end my life about this problem, do i have to provide them their bread and butter?it is really unfair since some of them are just depending on what will come.