Happened to me last year after giving birth. Mine was at waist length and poof no longer curling. It was just hanging there lank :S Then the mommy hormones kicked in and I chopped it off to shoulder length. It's now just trying to pass bsl.

Well not long after cutting it, my hair returned to normal and was happy again. So, hang in there and treat it gently. Trust me it will pass.
Mostly 3B/C with a multiple personality disorder!
CO-Wash: Curlicious Curls Cleansing Cream, Suave, Coconut Sublime
Leave In: My own mix,
Curls Milkshake, Curls Souffle

Stylers: My own mix
-great results with Aussie IF gel
-Curls Goddess Glaze
DT: Lekair Cholesterol, my own mix
Curls Ecstasy Hair Tea

PW: curlies