yea, you should try laying off the heat! If you must, like evryone said use a protectant.
Condition condtion conditon! Every single time you shower condition your hair. so if you shower 7 days a week, condition all 7 days. Only shampoo 3 of those days. I know it sounds weird and like your hair will be oily as all hell, but once your scalps oil production adjusts, youll be fine. The conditioner willclean your hair a bit, but it will moistly add much needed moisture. Youre hair will feel loads better. Once a week i would do a deep conditioning mask, like the moroccan oil. mask. When my hair feels particualrly haggard, i sleep in it, or leave it on my tips all day.
I would also use the morrocan oil before blow drying.
You can also try Redken's anti snap.
Also look into a keratin/protien treatment. I like aphogees, which you can get a sallys. they have a 2 min booster, which is pretty good. But the full treatment is hardcore. You can only use it 1 every 6 weeks because its so strong. I warn you, this stuff smells and looks like diarreah. i wish i were joking. You put it all over your hair (while gagging) and blow dry it. You hair becomes hair as a helmet, whatever you do, do not touch your hair while its in this condition as it can snap right off. Make sure its all blow dried, leave it on for a bit and wash it out carefully. it saved my hair after a nightmare at a salon (dying 3 times in a week, stripping the colour and dying it again!). I love this stuff for seriously stressed out hair.