HELP!!! i have to have a colonoscopy :-(?

im going in for a colonoscopy at 8 am Friday morning. im petrified, but know i have to do it to find out why i have a lump in my side, constant upset tummies and have lost a lot of weight. has any one got any advice that will make me feel better, or help me in some way with what i can eat leading up to the procedure? anything would be gratefully recieved,