I'm disappointed in myself-every time I try to help someone out it always comes back and bites me in…

I'm disappointed in myself-every time I try to help someone out it always comes back and bites me in the ass!. I just don't understand why I always have to go out my way for others but others don't care what it took for me to help them out and just go and mess it all up or throw it out the door like It's nothing.