Is it too late to get my natural color back?

I have terribly damaged hair from bleach, I went from my natural dark brown hair to blonde in 2010, a while later I dyed it black, and then a couple months later BACK to blonde, my roots are growing like a weed and I don't want to bleach it anymore I give up I regret everything I wish I could go back I learned my lesson and I just want my natural dark brown hair back. Is it too late? =( Is dark hair dye going to damage it even more? I would ask my stylist but you cant really trust anybody they'll tell you anything to get your money