Worried sick about bowel cancer

Hi everyone, this forum has really calmed me down as I'm a nervous wreck and I now don't feel so alone. So for the last 6 weeks I've had terrible wind and bowel gas. Especially in the early mornings I'm waking and constant flatulence. I also have some left side pain when eating anything and terrible indigestion. I'm eating plain foods like rice, bananas, chicken and can't tolerate anything else. My tummy is constantly making weird noises. My bowel movements are all over the place. Used to be so regular, now it's none for a day or two, some days watery loose stools other days normal size and shape. Only one one occasion was there a tiny drop of blood on the paper when wiped, barely visible.I'm also suffering from bad back pain and sometimes pressure in back passage relieved by flatulence. 
I had a pelvic scan due to fear of ovarian cancer but that was ok, radiologist said I was full of bowel gas and recommended a referral for colonoscopy etc. I also have heartburn at times. 

Im absolutely terrified. Can't sleep or eat with anxiety so am losing weight. I'm so worried it's bowel cancer. I'm 44 and was so healthy up to this sudden change. The wind and flatulence is the worst. Can anyone relate or help?
seeing a specialist in the next few weeks.  
thanks so much to everyone for reading this