Sudden onset severe lower abdo pain, persistent for 12days, as days go past can't eat, feel full after couple mouthfuls, feel sick, faint and unwell?

Go to the ER: Abdominal pain could be from a variety of reasons. In women, gynecological causes are common. Ovarian cysts, endometriosis, or uterine reasons need to be investigated. Bowel reasons such as inflammatory bowel disease, appendicitis could also be the reason. With your previous history of surgery (appendectomy)- bowel obstruction from adhesions is possible. See a physician.