Dont know what to do anymore, my husband picks on my 10 yr old.?

Mt eldest is 10yrs old and my husband is really horrible to her. I dont know what to do. He swears at her, always yells at her and puts her down, by calling her names and saying she is useless. Its effecting her so much so that she cries all the time and wont eat tea most of the time. She really hates her dad, and is a better person when his not around. I dont want to leave him, cause that would make things worse. But I want him to stop what he does. I've tried talking to him and he then does the woe is me thing and no one ever listens to him.etc,etc. I dont want my daughter to suffer from deep depression or anything like that. She always asks me why, he is like it and I cant answer her. I really need some advise to stop this going on. Also to make him listen and see what he is doing to her. How can I answer my daughters questions as well?