I had exactly the same problem with shoulder-length hair, sister! So I got tired, found a male stylist (don't trust women- they're jealous and hate to make other women look better than them; think about it) and went for a pixie cut. Bang! My hair instantly became thicker, straighter, more manageable, and softer. You might want to go for a shorter style, because in at least my case, the longer the hair the curler it becomes.
Also, as others said above, reduce to washing hair only once a week. My hair became much much healthier that way.