M.E.
I went through the same thing when i had my little girl. I cried everytime i'd think about it. The only thing i can suggest is start "practicing". Let her say with some one a few hours here and there to get her and you used to being separated. I only went back part time and over the last year gradually increased my hours. The night before you go back will be awful and the morning you leave her will be torture, but when you get home and see her there it will be almost as great as when you saw that little face when you gave birth. but every day after that will get a little easier adn then it will be no trouble at all.