Nothing you can do about it, but save up for a new paint job.
At this point, it is dry, scaly dust that is loosely held together. Think of it like a piece of coral, where the porous holes are where all the binding chemicals have evaporated out. All that will happen is you will fill those holes with wax that you will never get out, until you buff all the way through. Car will look like hammered shit.
Just a guess, the dark spots you mention are where someone else has tried to revive the paint before you and burned it with a buffer.