i have 3c/b hair and while i dont know any other natural curlies round here, i can only really give you advice on what i do, i believe that healthy hair growth starts from the scalp, so if it is indeed not growing due to damage, i would think bout cutting it off n starting from scratch like you thought. try taking hair vitamins, boitin is good when your growing it out,but i think for the first few months it might help if you take a mixture, so vitamins that are for hair.
I'm really fussy with what goes on n in my hair, and i generally only use natural things, so thats herbs, oils and that type of stuff. these no right or wrong answer with how to use them, its just about finding what works for you. i use a mixture of different herbs and message it on my scalp, which cleans my scalp and stimulates growth.
i agree with what thelio said about your moisture problem. try sealing you hair with a good oil at when you've washed your hair, this will help with future breakage.....
i shower at night so i can put all the goodies in my hair and let it to do its thing while i sleep but thats just me.
i hope somthing will help, good luck and let us know how you get on

my hair: 3b, high porosity, high density and coarse hair (i think i finally figured that all out)
my hair loves conditioner only styling!
Oils and my own procuts are my hairs best friend
my hair goal length is bra strap length when curly.