This can be a symptom of dysautonomia
I have felt this before. Occasionally I still get it. Have you ever had your blood checked for low iron during this time? I find that if I really pack up my diet intake with broccoli, greens, lean red meat, high iron cereal (total) a week or 2 before period, my energy seems to keep steady and I don't feel faint. I stay away from high sugar foods during this time to also keep from hi;s and lows of energy. Doesn't hurt to try, but I would check for anemia. Also, I take vitex (natural) for hormonal issues and helps so far.
Have you discussed this with your OB/GYN physician ? If not, I think you should consider making an appointment with her/him. Perhaps progesterone would help you.... ?