Its Gets Way Too Overwhelming

In my family, I don't know where to begin. I have a blended family, I love it, but it has it ups and downs. So much so that I feel that I no longer want to be apart of the family. But in reality that couldn't happen because I love my family regardless of all the crazy, selfishness and destructiveness. I guess I am immuned to the all the mishaps. At times I just wish I could just pick up and leave and move far away just to live life and not have to get involved with everyones elses life. And really its my sisters who are always asking for it, they want help, cry for help, get mad cause they aren't getting help, and when you do help there is hardly any thank-yous. I honestly think the biggest problem in my family is finding forgiveness, saying sorry, and of course saying a simple thank-you. Despite all the things that commonly take place in my family, I have to look out for me. I have been seeing this cycle of stuff all the time and it's run its course with me and I am tired of listening to the drama and feeling worried. I mean what it comes down to is you. Is it selfish to want to live your life as normally as possible? for me I feel its like ying-yang, I'll be there for my family, but it will depend on the situation. For example, if my someone is ill, for sure I'll be there to help, but if its things that personally don't affect me, like an argument, I'm staying out of it. I'm making boundaries, I am not going to allow myself to be intertwined with all the commotion that is really unhealthy and negative.