how to make my hair grow fast and healthy and so i don't have to wash it

[greeny]

all the time to keep it not greasy? i used to have long hair that everyone loved because it was a natural light brown with light blonde streaks and it was staight all by it self and on top of that it grew fast and it was healthy and it was all natural and it was long and then i started to style it and blow dry and ova time it not as healthy any more but then i cut it shoulder legnth and now it wont grow and it not so healthy and i wont it long again and on top of that i have to wash it all the time because it gets greesy HELP