Could I Have Colon Cancer ?

Hello. I found this site by google. First off, I m 19 years old, male, and English is not my native language. Please have that in mind. Since 2010 I have been experiencing great amounts of pain when I sit. It must be noted that I spend all my day at home, sat, since 2006. I used to weight 70kg by 2008, and now I weight 60kg. Somewhere around the latter half of 2010 I started experiencing pain when I sat, in the span of just a few days, after a pointy, itchy sensation inside my anus. When I went to the bathroom and used hygienic paper to clean myself, it was full of bright, red blood in really big quantities. At first my family thought it was an hemorrhoid. I went to two proctologists. The first one identified it as an hemorrhoid and recommended a simple local pain-alleviating medicine. It didn t do anything to cure it. I still couldn t sit on hard places, and I would often experience some kind of bright red blood after going to the bathroom. Since that time, my stools have been really big, hard, and no cleaning with hygienic paper are needed, for they are very dry, except when it bleeds. The second proctologist identified it as an anal fissure , and recommended changing my whole diet , and suggest some medicines. That was around october or november 2010. Even following all his recommendations, and going to the bathroom every day, my stool is still too hard and dry, and I still experience bleeding . He also said that my pain on not being able to stay sat could not be caused by an anal fissure, and that I should check with an orthopedist . My researches have led me to believe I have either coccydynia or colon cancer . For the record, I can t stay sat unless I use donut-like cushions on the top of very soft things (like my bed). And everytime when I bleed, it s always bright red blood. Considering my age, I think it is unlikely that I could have colon cancer. However, I can t seem to get better from this condition (like I should if it was anal fissure or hemorrhoid), and I often experience fatigue and a feeling like I can t concentrate on something. And while coccydynia is associated with not being able to stay sat because of great amounts of pain, it has nothing to do with defecating hard, dry, stools no matter your diet, and bleeding bright red blood. I m honestly hopeless and depressed. Do you believe I could have colon cancer? Don t be afraid to say what you really think, I won t get more depressed, and I just want to avoid other possible painful, invasive and expensive measures I could have to pass through to check unlikely health problems. From the bottom of my heart , I would like to thank greatly anyone who reads this fully.