Why does my hair get so frizzy?

okay I have mid back length hair naturally curly. so why is it when I out of the shower at night and I leve it down and in the morning its so curly and perfect and not frizzy at all and then when I put on my curl definer its still like that but when I...

comb it just enough to get the knots out all the curl falls out and it gets monsterously frizzy?

well im not really sure,but my hair is pretty much the same way. I have the natural full,thick curly hair that frizzes out no matter whut. but I straighten my hair every day and it keeps it tamed and healthy looking. also I just started useing paul mitchell's strength shampoo and conditioner,plus I have the spray that I spritz all over while my hair is still damp before I brush my hair and it makes it more healthy and less frizzy. you should only get this stuff from your local hair salon. I was just recently told that the hair products in the stores are not whut you think they are,they have way more chemicals in them that will damage your hair. thats whut my hair stylist told me. cost me almost 200 bucks to fix my hair.