Try Care Free Snap Back Curl Restore, you can find it at Sally's.
First do a deep conditioner, something rich, to bring moisture to your hair. Rinse it out bit not totally, then towel dry and apply the Care Free Snap Back Curl Restore. Then you can also use the Curl enhancers from the same line.
You will notice how the hair start shaping up in a few days.
This routine saved my life many years ago when I fried my curls and ended up with a dry straw looking hair. Hopefully it can help you too!