My cousin who had type 4 curls went through the same. her curls haven't come back either, but she seems to like it.
I am loosing my curl as well. I believe it to be hormonal related, although I am not pregnant or have had a baby.
My hair used to be 3a. Now it is getting more of a loose wave and it seems softer and smother, but I still prefered my curls. I want them back!