Your hair and your hair history sound pretty similar to mine
I started CG in April. I have coarse, mid density, 2c hair. I straightened for years and learned a lot about straightening along the way. I noticed a while ago that when I wore my hair curly it was really only curling at the ends and in the front. The rest was just sort of a frizzy not-straight, not-curly blog :P I thought that maybe it was because I had cut my hair shorter (above my shoulders) and that for some reason my hair wasn't curling at this length. Then I found an older picture of my hair the same length but my curls actually looked pretty good. I stumbled across livecurlylivefree.com and I haven't thought of my hair the same way since. I decided to give it a try (though giving up straightening has been very very hard for me) and I am starting to be pretty happy with the results.
My hair is healthier than it has ever been because this is the first time I have ever cared for it properly. It is shinier and the color is richer because it doesn't have that dry, dull look to it. Also I'm starting to notice an increase in my curl definition in those places that weren't really curling before. I number one thing I notice is that my hair is a lot bouncer. I read a lot about hair elasticity, and apparently, in addition to dryness and heat damage, straightening really breaks down your hair's elasticity (ability to bounce back) partly just because of the constant pulling and tugging of straightening.
I've been using Suave naturals (I like that it is a little bit lighter feeling instead of really thick like some conditioners) as my Co-Wash and leave in. I recently started using Nature's Gate shampoo once a week and have been happier with the results than when I was just co-washing. I first used Goddess Curls Gel but have recently switched to goddess curls creme brule and I like it a lot better. It seems to do a good job of holding my curls and keeping my frizz in check, but it doesn't make my hair crunchy at all. It keeps my curls bouncy and soft looking instead of giving them that wet stringy look.
I have yet to conquer 2nd day hair without a complete shower drench
or a headband. It seems anything short of a complete drench, leave-in, product, air dry routine leaves the top of my head really frizzy. My hair takes most of the day to dry so I prefer to not wet it so much. And if I go out in the humidity before it is dry it tends to frizz. If you figure anything out for 2nd day I'd love to know
Good luck with CG! Id love to hear how it works out for you.