Metal Gear Solid 3: Subsistence

You can't kill the Sorrow, kill yourself and take the revival pill.

there are two ways to kill the sorrow, one which is the easiest and quick is to try to swim and drown yourself at which time you can take the revival pill and wake up. But the best way to beat it and get the sorrow camo is to just keep walking up the river which is filled with every soldier you killed (not tranquilized or knocked out). All you have to do is just dodge the soldiers and blasts from the sorrow and you will die at the end and take the revival pill. And thats it, you have beaten the shadow and acquired his camo which makes your footsteps silent no matter how fast you walk or run and when you choke an enemy you gain stamina PRETTY HANDY ON VERY HARD!!

Tactic 1: Drown yourself. you don't get anything special.
Tactic 2: if your doing a No Kill run, avoid the Cobras, or if you killed little - many people, use the Fork, and reach the end of the river. either way you die, but if you make it to The Sorrow's body, when you get your stuff back, The Sorrow Camo is in your inventory.

Maybe you dont have the revival pill assigned to your menu thingy?

When you die you have to physically hold in the L2 with the revival pill showing..then hit O ..if you don't hold L2 down and hit O you go to continue and thus have to start the Sorrow river over again.

You can spend your time going across the river until you find his corpse and keel over. Then when it's like "SNAKE IS DEAD!" open the item window (L2) and take the revival pill. You get the spirit camo for it, and if you combine it with stealth camo you become completely invisible. Or if you don't want to wast your time wading through the river you can just take the fake death pill at the start of the fight, then take the revival pill. But you don't get the spirit camo if you do that.

well it dependes do you want the camo from the sorow or no? if not you can just kill yourself and take the revival pill(by Drowing).if you want the camo you got to walk all way till you can;t walk no more the you will see the "SNAKE IS DEAD " screen then you should be able to press L2 and take the revival pill.

Just walk up the river until you see a skeleton, a game over screen will pop up, use the revival pill to wake up from the nightmare. You get there faster if you don't kill anyone in the game.

IT ONLY LOOKS LIKE THE GAME OVER SCREEN.
If you open your items menu, you will find you can use the revival pill.

You keep going all the way and at the end die and use revival pill