PMDD (premenstrual dysphoric disorder) is a severe, recognised condition — not just "bad PMS." It causes marked emotional and physical symptoms in the luteal phase (the roughly one to two weeks before a period), especially depression, irritability, anxiety and mood swings, which significantly disrupt work, relationships and daily life, then ease soon after bleeding starts.
It's thought to involve an unusual sensitivity to the normal cyclical changes in estrogen and progesterone. PMDD is treatable — tracking symptoms confirms the pattern, and clinicians may offer options such as SSRIs or hormonal approaches. See PMS and PMDD. Any thoughts of self-harm need urgent help.