I need help!

[camille_07]

I am not actually an oesophageal patient. I undergo appendectomy last 3 years. I have gastritis for atleast 5 years(if I'm not mistaken). I am only 15 years old. I am a girl. I like barbecued foods. I also like salty foods. I suffered constipation to the point that there is also blood but now, It turned to a slight diarrhea. my stool now is darker than before. sometimes, I feel heartburn. sometimes, when I inhale deeply, my chest hurts. last night, I started vomiting. my family has medical history about cancer like brain tumor, breast cancer, and colon cancer. I think that I have stomach cancer but I don't want to consult a doctor. Do you think that it is possible that I have cancer?