What can I do to fix my incredibly dry curly hair?

I'm biracial, and I have curly hair. It probably is more damaged than it should be. I've dyed it a few times over the years and flat ironed it as well, but I have stopped dyeing and haven't flat ironed it in a year or so. Anyway, it's SOOOOO dry—when I'm done washing my hair, (unless I put something on it) it completely shrivels up and becomes this horrible dry mess. I found this amazing product that works for my hair (it weighs it down and moisturizes), but I can't use that forever. I want my hair to be naturally moisturized. I feel like all the natural oils are gone, which is funny, because a couple of years ago, my hair was TOO oily. I don't know what to do to make my hair healthy/moist again...I don't want to have to depend on a product to do that. Help?