hello mam! intra uterine devices are notorious for the kind of symptoms you mentioned. loss of appetite can be multi dimensional. your abdominal and lower back pain points towards pelvic inflammatory disease. add folic acids with A to zinc vitamins with ferrous sulphate. this will help your appetite. other reason for appetitie loss can be the routine or stress. you need to have regular 8 hours sleep use some sleeping aids for short duration if necessary. tireness and fatigue and headaches are also because of loss of appetite and PID. try some antispasmodics for the pain and simple acetaminophen for the headaches. and if the symptoms persist you can always remove your IUD and use some alternate contraception. remember IUD is a foreign agent to the body and any foreigner is never welcomed. it adds to the adhesions, reduces the fertility rates. increases the chancess of ectopic pregnanciess,, Ashermans syndrome, Pelvic inflammatory diseases and discomforts etc. So you need to try coping up or give up and start an alternative way to contraceive. cheers