Hi Sheila - I experienced this after weaning both my babies, and I have just had two sisters go through this in the last twelve months. I discovered that mine was caused by iron deficiency - pregnancy and breastfeeding saps your iron stores and then when your period kicks back in after weaning you lose even MORE iron. The coincidence with the timing of the cessation of breastfeeding and your period resuming can easily trick you into thinking it's hormone-related.

Iron deficiency (and it doesn't have to be anemia, just a low hemoglobin count is enough) can cause tiredness, dizzyness, insomnia, restless legs and irritability. I was put on meds first and when the symptoms didn't abate THEN I got a blood test - after less than a week on an iron supplement I was a new person. My sisters reported the EXACT same response to iron supplementation.

I eat a really healthy and balanced diet, but it was just not enough to replenish my iron stores and I was always at rock bottom. Obviously you want to check with a doctor before going on a supplement, but it's worth suggesting to them - it changed my life, honest.

Good luck!