I put blonde highlights in my hair ....?

in august of this year but the lady that did it left the bleach on way to long and all the ends of my hair are like super gummy liked dead and my hair was really healthy before i did this ive been trying everything to get my hair back healthy but nothing seems to work i want to take the blonde completley out of my hair so i wana just dye it all one color. ive waited 3 months now and was wondering if anyone has any suggestions on what i should do i cant do nothing to my hair i have to keep it up all the time... would it make it worse if i dye it all completley? or is there anything someone suggests to make it healthy ??