Pain moves from my stomach to my back

I am 28 years old man and I have been having stomach discomfort; this pain moves from ma stomach to my back and the problem has been on for the past 7-8years now. i have done check up with some doctors after which nothing was found.at first i thought it was ulcer and i was taking medication base on that, I even went to a doctor that carried out some test and the doctor diagnose and said i had H pillory. he gave me antibiotic. but after the treatment the pain still continue, sometimes my body system changes also i notice that i have dandruff on my head. Each time i try to scratch i see something like dried pose coming out from my head. Recently i went to a different hospital and i told the doctor how i feel he suggested i go for endoscopy. I did it and no ulcer was found I also did ultra sound still nothing was found. i don`t know what else to do. The doctor said my stomach is good. But i am still suffering from this pain.