Dark Brown to Platinum Blonde?

I was on the same boat as you, same time last year i decided i wanted to go from black to platinum, just because it faded doesn't mean the dye isn't there, there is still black dye and it will take bleach to get you to what you want. it took me 3-4 bleachings over the span of a year to get to the platinum blonde color (thats witth me going to a professional to have it done, getting a lot of hair trimmed off, tons of deep conditioning treatments, and the ended use of heat styling tools). my hair looked like a dark brown and i thought it would be ok but even a 40 volume bleach couldn't get it that high in one shot. but dont be discouraged, im just trying to make sure your hair doesnt fall out. i recommend doing the bleachings slowly with at least a month in between each one and getting trims. my hairs very dead and i went at a really slow rate, going that fast could cause your hair to fall out.