I Have Been Feeling Ill For Quite Some Time, Occassional

I have been feeling ill for quite some time, occassional fevers, constantly tired, all over pain, constant nausea, i can sleep for days, dizziness, and weird feelings like my nerves are firing off through out my body, like when i turn my head or move in general the nerves are over sensitive, the nausea last days. doctors keep telling me its general fatigue, but i just dont feel right, i feel like something is wrong. i have an abscess in my jaw bone, and i am wondering if that could be the problem.