Post Menstrual Syndrome is usual in the 10-14 days prior to a period, once the bleeding begins the symptoms should recede. It's a 'natural' cycle though can be damning!
I was advised by the National Association for Pre-menstrual Syndrome to eat every 3 hours, 24/7. Not to eat more but to spread my diet throughout the day/night, I had a puppy at the time and she soon learnt that biscuits were to be had in the early hours after going out for a P ;-)
My go-to foods have been: dried fruits and nuts; bananas; ginger biscuits; dried Kellogs flakes in small boxes when travelling ; lots of cooked chicken dishes with veg., ginger and garlic; chicken curry with rice: trying to eat B4 my energy levels dropped = nausea.
Some find that keeping a mood/food/symptom diary of use. Let us know how you get on.