i had the same problem!! what i tend to do is after washing my hair putting a thick tea tree mask on, have a towel heated in the microwave and wrap my hair in it!
i rinse that out after about 10 mins, i then put in an elixer for your hair called Oroflu~do, its not too thick but using only a small pea size is enough, put this into your wet hair mostly on the sections that tend to fizz worse.
then when your drying your hair point the nozel of the dryer downwards so the hair is not being roughed up and made damaged and will result in being frizzy.
if you need to run the straighting iron over your hair and again put a very small blob of the elixer in again, that should do the trick
