How to make my hair grow?

well i used to straighten my hair everyday and its very curly. it never gets greasy so i wash it once every one-two weeks . but now i only straighten my hair after i washed it i used to use hair protection but it makes it look greasy and knotty and i nd to wash it more. its not the fact im lazy its just when i wash it it needs to be straight end completely. what can i do to make my hair grow over th summer? please don't say leave it natural because i hate my curls as they are mainly frizz. oh yeah by the way is their anything i can do before to make it straighter so i have to put less heat on it. by the way my hair hardly grows at all and its Pretty much dead , and no i don't want to gt it cut or Trimd. if anyone can help evn if its not even to do with this it will all hlp thanks