I can feel all the symptoms of my monthly cycle with no cycle. i'm so weak , been sleeping for 12 hrs or more straight. and i feel like vomiting. why?

Painful: Ugh, that sounds so painful. Your hormones are likely causing these symptoms. While not unusual, it doesn't take away from the fact that it can be miserable. Premenstrual symptoms like this cause increase in prostaglandins which cause pain and changes in the gastrointestinal tract. Ibuprofen can help, taking birth control pills and skipping placebo week can help too. See your doctor for option.