Hair looks fried when I straighten it?

My hair is curly and frizzy. My dad had extremely curly ringlets and my mom has waves, so put me in and you get an awkward, in-between sort of combo. It's not to the point of African hair, but it is halfway there (thanks to my dad). When I straighten my hair, I use a heat protectant and wash it a couple hours before. I usually go about 360 degrees, and I straighten small pieces at a time. This is what I want it to look like: 
And this is how it turns out:
That's a little exaggerated; it's not quite that bad. But still! The first day it might feel a little itchy but by the second day it's like horse hay. I use protectors and wash my hair before; can I make this stop happening??? I don't straighten my hair that often because I'm lazy, but I do it about two times a month to switch things up (and get rid of that nasty frizz). I don't want to have to stop straightening, but I feel like my hair is super damaged by it.... Tips pleaseeeeee