blood in the stool

I am a 31 year old woman. For about a year now i have had constant blood in my bowel movements.I have been checked for hemroids and do not have any. My iron is constantly low and i am exstremely tired all the time. I have a constant low grade fever and and pain in the upper right side just below my rib cage. I have limpnodes swollen all over the place. I am terrified that i have something really wrong with me and i cant get my doctors to listen too me.I keep getting told that it is stress and all in my head. I am really stuck on what to do next I have to have a referal with my insurance. I dont know what to do.