Getting colonoscopy on Wednesday for the first time I'm so scared

I am 24m had loose stools since October booked for a colonoscopy with biopsy on Wednesday I have suspected colitis but I'm worried about cancer also my white blood cell count was 14 and came back down to 9 not sure if white blood count rises during a flare up? I have 2 loose bowel movements a day and have seen blood, mucus and undigested food on separate occasions I have shoulder and shin pains with rashes on the skin that don't hurt or itch abdominal pain has come and gone and sometimes comes back I'm freaking out my calprotectin was 72 when tested has anyone shared the same symptoms? I am freaking out I've got something life threatening I'm a complete mess anyone who can share experiences and same symptoms and put my mind at ease? These bowel problems has also caused massive health anxiety :(