My hair takes more then a hour to straighten ! please help?

ok so im really frustrated i take like a hour and 30 Min's straightening my hair ! i have a lot of hair its long and poofy and curly : ( i use a conair straightener that goes up to 395 degrees farenheit. i get really sad and discouraged and i want to start straightening my hair more often and yes i use a serum to protect my hair from heat (john frida i think) please do you have any tips!? any striaghtener that goes at least up to 500 degrees and how long it would take to straighten my hair with that certain straightener ? please help : ) any ideas. please please help