need some help

hi there. so my natural hair is an lighter brown but i ve been going blonde for a little while and so i dyed my hair like three months ago and i was really satisfied with the look i got. but my roots were really starting to show so i decided to dyed it again. i also wanted to go a little bit lighter. but my hair right now is platinum blond with purple stains all over the back of my head, i really wanted a more lighter and natural look but ruined it all. i am trying to get my hair to a natural blonde with some depth and dimension. do you think i could fix it with some hilghits. i was thinking of going in with an 8 or a 8.9. i also use a highliting cap.

i really need some help my hair is a hot mees rn.

any advice?