I still haven’t found an infallible method and would be very similar to you with the wavy/curly 2c hair which I straightened the bejesus out of for 25 years also!
I went through a several week period at the start of the curly journey of “this is a complete pain in my ass” with hair being like an absolute nest in the mornings and either having to fully wash it every day or revert to straightening/brushing it out and whacking it into a bun.
Stuck with it though and my hair now seems in much better condition so behaves better. Now, there is still no way I can spring out of bed in the morning and shake loose a glorious mane of curls, but I tend to pineapple it with a silk scrunchy or pile it into a silk turban, shake it out in the morning (looks like hair explosion) and then dampen it with some water to sort of calm it down (don’t need to wash it or even soak it except for sometimes giving the front bits a good wetting to get a more attractive frame of curls round face if they’re looking a bit shite), then pat through a decent splodge of curl cream and scrunch it up into curliness again (using a dampened cotton T-shirt over my hand for the scrunching).
If I have time I use diffuser to dry it as it tends to set the curls better, if not just let it air dry while I sort kids/breakfasts etc. Then scrunch out the crunch and go.
Works 95% of the time and the other 5% I have a selection of nice hair scarves and clips to shove it up and hide it!
I’d also highly recommend getting a curly cut and style, if only to have hairdresser show you how to properly wash, style, and diffuser dry your hair for your twice weekly (or so) wash day. I did it for the first time a few months back and it was a revelation. Really feel like I know what I’m at now!
Stick with it. The big thing I’ve found is even if I’m having a bit of a “meh” hair day I get loads of compliments because people just seem to see the curls, not the frizz! (I still very much see the frizz).