What to do with Frizzy Hair in Humidity...

I have incredibly coarse, thick, naturally curly hair...and a lot of it. Now some of you may view this as a blessing and I realize it could be worse. But it is an uphill battle most of the time with my hair in a humid climate such as Southeast Virginia. As a side note I've also done a fair amount of stuff to my hair in the past year like dyeing it and then having the color stripped off so it is a bit damaged on the ends. So when I was having my hair cut last week my hair stylist suggests Keratin Complex Smoothing Therapy. Unlike other straightening treatments it involves protein instead of chemicals so it actually helps your hair. It is a lengthy process as in 4-5 hours because they put the protein on and then flat iron it multiple times to seal it in. It is also costly...for my amount of hair they said it would be around $250-300. But they said the difference in my hair would be night and day. Currently I just can't justify the expense but I'm thinking it might be something in the future. We'll see.

Any of you have advice for frizzy hair?