Cookies are pretty forgiving recipes, so for heaven's sake, don't throw your ingredients out!
Since I don't know, however, exactly what the function of first creaming the butter and sugar is, I just checked in my handy-dandy baking science book (How Baking Works by Paula Figoni .. a book I talk so much about I'm sure you all think I'm getting a commission). Here's what she said about the function of creaming:
"Fats assist in leavening in three main ways. The traditional way is in the creaming of plastic* fats, where tiny air cells are incorporated into the fat. Cookies and cakes made by the creaming method rely on plastic fats for the bulk of their volume and fine crumb. This is true even when baking powder is used."
* plastic fats evidently just refer to the texture, i.e., soft and malleable -- butter in this case
So I'll betcha it will just be a texture issue largely, maybe a little bit a volume issue. Can you deal with slightly more coarse and maybe slightly flatter cookies??