You have many symptoms which do not sound as though they are directly related other than that stress
or certain intestinal infections can be the cause. Your abdominal symptoms sound like Irritable Bowel Syndrome
(a functional disturbance of the colon). Your headache sounds typical of a cluster/tension headache
. The clicking of the body might be arthritis
You must see a doctor to examine you, and possibly send away a stool sample, to exclude infections of the bowel, this is not something you should neglect as it can make you very ill.