I truly second to stop brushing your hair. I also agree that you should do some searches on here to pin point great starting Co-washes, Leave in, gels, etc. to begin your hairs transition. Definitely
look up and read about the Curly Girl Method. It helps by giving you a starting point at which to begin so you don't feel so overwhelmed trying to search on here or google. Unfortunately, the more you continue to straighten, the more you are setting yourself back with your curls. At some point, you should take the commitment and eliminate your straightener for good (I know it's hard, but it can be done!).
This site has amazing information on whatever you are looking for. But I think you should begin by reading about the Curly Girl method and understand it so you know what to look for in products.