Hello, I have gone through your question and understand your concern. The cause of symptoms could be excess stress and diet modification. It is less likely to be caused by pms. I would suggest you to relax, keep your self well hydrated, and if possible get your blood pressure monitored. Since, excess physical strain, and sweating during fitness routine can lead to dehydration and hypotension. I would advise you to take oral re-hydration fluids, and if the diet you are following permits you can even take vitamin B complex supplement as it helps improving energy. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Ayesha Shareef, General & Family Physician