getting hair back from black?

TBH if you put black dye over previously bleached hair you are unlikely to be able to get back to blonde. Black dyes stain, especially when the base is light and/or porous.
Start with colour removers, you will need to do at least 3. I find them more effective if spaced out with regular fading treatments in between.

noo my black is not over blonde, all my blonde was long gone before i did the black. 🙂 i went brown like right after which was three years ago. and waited for all the damage to grow out because i even touched my hair with any dye. I've only been black for a year. when my hair was multicolored it was pretty short. so its deffo grew out by now 🙂 right now my hair is just black over brown.

If your hair was virgin when you put the black on it is less likely to have stained, but dyed black to light blonde is still a big transformation that will take several months if you want healthy hair at the end.
See where you are after three colour removers, you will probably have dark ends and much lighter roots, and you can then start gently lightening.

Well, my hair was totally damaged after bleaching... I shaved off one side (I was like a real punk-girl) and was waiting till it grow out. Now everything is not so sad 🙂