Can't eat sugary foods, craving milk, cramping, missed period, lower back stiffness, headaches, mood swings, constantly tired, watery discharge?

See your PCP. There are a number of conditions that can present with your symptoms. You could have a urinary tract infection, kidney infection hormonal problems especially since you have missed periods, sugar problems, among other things. You need to see your pcp who can get a series of tests to sort out what is wrong.
Symptoms. You have multiple symptoms so it makes sense to have a complete physical with your doctor and if cleared medically seek out a clinical psychologist who can help you identify the causes of your distress and can help learn better ways of coping. My best.