How to fix dry, damage, frizzy hair?

I'm 17 and I have had dry, damaged, frizzy hair my entire life and I have no idea how to fix it. I have shoulder length hair and it doesn't seem to grow any more. I use paul Mitchell original shampoo and conditioner. I have bleached my hair twice and dyed it countless times. I've tried deep conditioning, cutting all of the dead ends off, and home remedies. How can I fix my hair for good?