Hey!
Singing metal is a real skill to do wihtout doing irreversable damage to your vocal chords. I would suggest taking a break from screaming for a bit because your throat should not be hurting if you are doing it correctly. They to it all is to use your "false" vocal folds. This technique protect the tender delicate ones that you usually use for speaking and singing. But how do you know if you are using the false folds? That is something you need a good instrutor to help you with. You need a coach with the right ear and expertise to help you learn to use the false folds and strengthen your voice so that when you scream, you will still be able to sing and you'll still have a voice. This is the technique used by pro metal singers, and it's how they do concert after concert and tour after tour and can still put on a great show vocally.
Michael Maresca is an excelent teacher for this kind of stuff. He like specializes in all kinds of contemporary vocal styles, and he'd be a great help. And trust me, the lessons would be worth every penny if they can save your voice from potential annihilation!
www.mmonevoice.com
That's his website! When I started taking lessons with him I couldn't belt, and all I could do was sing operatically. Now I can sing like ANYTHING! I'm serious. Check him out!