I just went through this myself. I had my hair BLACK for years. repetitive dying with uber strong dye = years of undoing. i'm almost back to my natural (very dark auburn) color and have been intensively conditioning and getting very regular haircuts. I got l'oreal intense repair. i shower at night, put this stuff through my hair, put on a shower cap, do all my before bed stuff, heat it up with a hair dryer, and sleep on it. shower in the morning as I normally do and my hair is MUCH softer, this helps immensely with dry ends, splitting hairs, etc. I would have lost soo many inches to unnessecary cuts without it.
also, even if your hair IS curly/frizzy/unmanagable.. there are ways around heat styling. there are always braids (depending on hair length) there are clips for shorter hair, there are products that straghten your hair without heat (got2b//bedhead has some, i believe) just try new things... i went through some damn ugly hair phases to get it to where it is (almost the small of my back and HEALTHY hehe)
<3
hope that helps some!