I'm confused when you say that your hair looks best after it's washed, THEN it becomes frizzy. Do you mean it looks fine when it's wet, then looks frizzy when it dries?

If that's the case…
Washing removes oils and makes dry hair frizzy, so you can either put oil back in (like Luster's Pink oil or some other leave-in conditioner), dry your hair with a hair-dryer with a diffuser (don't let it air dry) or don't wash your hair very often. If you have that dry of hair and you wash it everyday, your hair will actually look worse than if you wash it every 2-3 days (or once a week, or like me, once every 1-2 weeks). And you can always use "dry" shampoo to remove the oil from your scalp area in between the times you wash it with shampoo/conditioner (with your type of hair, it would probably be beneficial to use conditioner). My hair is rarely frizzy now because I do all of that (and use a bunch of other products as well) even when it's really curly.