don;t how much more I can take

I am really in a pickle because I can't punish these kids that aren't mine but yet I have to make them behave.  I am not sure how I can do this, when I yell at them about something they turn all around when they tell their dad and they do tell him.  They make everything into a big deal and even when it's something as little as me telling them to not punish their brother because they are not the parent. One of them finds it ok to yell at me but when I do it back, I am made to be a horrible person. I love my husband very much but this getting to be to much for me.  I feel when it comes to all three kids that I never do anything right in my husband's eyes.