...Would a diffuser help that much if I have to dry it?
Diffusing helps me get a more consistent wave pattern. Also, rinsing upside down seems to help. Finally, I've been learning to "plop". (Click on "search" in the upper left corner of the page and look for "plopping".)
Sporting: Long hair that can't make up its mind. Wavy? Curly? Straight? It's anyone's guess!