Hi, Thank you for your question. These symptoms of headache and mood swings are most likely related to irregularity of menstrual cycle due to hormonal imbalance. Stress is considered an etiological factor in such hormonal disturbances. I would advice you not to avoid too much stress, change is practical phenomenon of life. Additionally, consult a gynecologist to rule out other causes like iron deficiency, folic acid deficiency, polycystic ovary etc. Hope this helps.
Sounds like it could be anxiety and depression. Have you had a good physical exam recently? Check out the anxiety and depression forums.
I would suggest that you get your hormones checked. Cortisol, thyroid and androgens would impact mood, tummy and your electrolytes and vitamins.
Have you seen an endocrinologist?