What Causes Prolonged Loose Stools, Body Ache, Insomnia, Fatigue And Memory Loss?

i have been suffering from uncomfortable gut,loose stool,body ache,memory loss,shortage of adequate breathing, disturbed sleep,underweight,occasional bladder problem,continuous fatigue, intestinal cramp and few more for the last 16 years. doctors found nothing and was pescribed antidepressant . i took it for 5 years then stopped a year ago.can you suggest me?