What Causes Appetite Loss Along With Backache And Abdominal Pain?

i suffer from alot of auto immune disoreders.i am 47...been on and off throughout the years since 21 years of age...i got endometriosis,slight lupus,some drs say i may have sjogrins syndrome,some say i am slight aniemic...no ive got alot of female issues going on.....i got loss of appetite,chronic lower back aches,feeling full after eating or barley eating much before getting done eating,lossing wieght,not really gaining any,lower adominal apin,i feel headaches off and on,theres times loss of breath,and heavy breathingand and lathargic