If I could have some advice it would be appreciated as I'm losing my mind with fear. 

Two months I noticed a large amount of maroon coloured blood in my stool along side having diarrahoea every 2 days. This lasted about 3 weeks so visited the Dr who did a blood test and took two stool samples. (He said these came back fine and the stool sample showed no sign of inflammation) 

Since the visit ive had chest pains and I have a pain under my left rib which hurts more when I laugh/cough etc which is making the anxiety so much worse as I've associated these pains to the cancer spreading. My stomach constantly is making gnawling noises too. 

After the the visit I rarely check my stool has it just makes me cry every time  I see  blood, but when I do check it's a really dark colour which is scaring me as I know that's a sign of something more serious.

i am waiting for my colonoscopy appointment which is in 3 week but I'm sick with fear, I feel like I'm drowning and I'm constantly crying and isolating myself. Even when I try and do normal day to day things my mind is so occupied with the thought I might have cancer that I simply can't do anything normal. I'm so worried. 

Some questions I have is - Has anyone had blood and stool tests come back normal and ended up having colitis or some form of inflammation. This is what I'm hoping I have as compared to cancer.

and second has anyone had symptoms which convinced them they had cancer when it turned out not to be?

Im new to these forums so I apologise if this post is too long, Thanks