My Health, Please Help With Advice!

I know the best thing is to go to a doctor, but I have been living outside the states for 7 months, and that is not the most easy option for me now. I was in russia for 6 months and now in norway for the last 1 1/2, and will be here until october. Now, 2 months before I left the us, I have been exhuasted beyond belief. I never feel rested, and it kicks my butt to do too much physical activity. I have joint pain often, nose bleeds occasionally and bleeding from my rectum, and just now, I am getting a little pain in my abdomn and in my lower back. I feel dizzy at times. The worst part of it is that I am a 22 year old male, and I should be in top condition! What could this possible be, cancer? Somthing else? I do not go to the doctor often, I do not like to, but I am concerned enough now to start some research...Can you help me with anythought or advise?