I think since your hair is really damaged, it might be best to just dye the whole thing your natural color! Also, have you thought of dying it like a dark brown or black? :) It might look cool and you won’t have to bleach your ends! But yeah I think if you want to keep the light blonde it might look weird because your roots will grow out and you’ll always have three “layers” of color in your hair! :P I hope this helps, and thank you! <3 Your English is good, don’t worry!