Hair is losing curl & definition

I’ve had 2c/3a curly hair all my life. It used to be super frizzy and messy but about 6 years ago I started putting effort into treating my hair according to its type… I started having good results and loved my hair. I’ve had two kids, my oldest just turned two, and since my 2nd I have almost completely lost all curl and volume to my hair. Even if I have some curl after it dries, it’s fallen out after a few more hours. I’ve tried so many different drug store products but want some advice before splurging on more expensive products. Currently I do not have a routine or a product I like, and am looking to start completely over. One thing I’m pretty sure of is that my hair is over moisturized… so I’m maybe in need of protein?Should I try olaplex? Or the redken curl line? Should I just accept that my hair is never going to be as curly as it was? Any help is appreciated.