I dyed my blonde hair a dark brown/black color. After I stripped it out, it is a light brownish color. Is it safe to dye it blonde, or should I cut my losses and blend with highlights? (wait, CAN I highlight it?)

If I were you I'd use salon quality moisturizer & protein treatments before touching my hair with anymore chemicals. Unless you don't mind having weak mushy strands of hair & getting a few inches chopped off.