welcome to health care magic
Your friend is probably having "Pre Menstrual Dysphoric disorder" which consists of anxiety, irritability, depressive symptoms prior to beginning of menstrual cycle. Breast tenderness and hot flushes can also occur in that period. Since she has delayed periods and dark red clots, visit to a gynaecologist is needed initially. After that she should visit a psychiatrist
for some medication like antidepressant/antianxiety agents
to alleviate those symptoms.
Hope it helps
Dr. Gourav Monga