I have 2b/3a hair and can get really spirally, depending on the weather.
One thing I found with my hair is that even a non sulfate shampoo can be drying if used everyday. And that results in less curls.
Why don't you try co-washing for 2 days in a row and then using a nonsulfate shampoo on the 3rd or 4th day? I started out doing that and now I only use a non sulfate shampoo maybe once a month when my hair starts to frizz from being overconditioned or build up.