I have the same problem .For me its definitely the cold weather . I was just looking at my hair last night thinking I just need to hold out til summer and I'll be happier with it .
My hair has such tight curls in the summer . As soon as the cold hits they lose curl . If I condition too much it gets even more droopy .
I'm still trying to find a good winter routine . I even broke down today and used shampoo but I don't think it made too much of a difference .
I hope you find something that works for you . I'll be watching this thread for more ideas.