Could I have stomach cancer?

I'm 19 years old, about two years ago I started to have painful stools with blood on the toilet paper. One doctor said I have an ana fissure. Then I went to another doctor about 7 months later and they said I have high stomach acid from eating too many spicy foods. I took medicine for awhile until it ran out. Around a year later when I was 18, I had a very severe headache one day, I took acetaminophen for it and it cut out a majority of the pain. About a week later I woke up with no appetite what so ever. Almost a year later, I still have a loss of appetite, I still eat though. I don't really have much stomach pain, if any it's very dull and rarely happens. I still have bloody movements, mainly on the paper after wiping, but I did have black tarry stools, twice. Once after eating chili and once after eating arbys. I did notice once I had diarrhea but only a few piece had blood in it. Most poops don't hurt anymore, I just still have the analysis fissure. What could this be, stomach cancer? Colon/rectal, colorectal? Peptic ulcer?