J.S.
omg! My hair fell out SO much after I stopped breastfeeding. It was quite alarming for me too. And while I had always seemed to "shed" hair everywhere, it was falling out in what felt like handfuls for me. My hairdresser said it is totally normal, but it still sucked!! :(
My hair was long & dark, and it was everywhere!!
And now, my son is 2 and a half and my hairline is just now getting back to normal. The actual falling out part lasted for about 3 months. it usually happens 6 weeks post-partum, or after you stop BF'ing. Maybe it has something to do with the prenatal vitamins, so I continued to take them even tho I no longer needed them. It helped.
Good luck!