Golyghtly colonoscopy prep?!?!?

I am a 17 year old girl who tomorrow i have to get my first colonoscopy. I have been prescribed Golyghtly. And it is AWFUL!!!!!! now, i have already drunk half of it and i have the rest tomorrow. BUT tomorrow i cant drink ANYTHING BUT the prep. Does anyone have any tips. I've got my prayers. That's about it. Please please please help me.