There were a few feeling Sam absolutely hated. The loneliness when the people they had saved chased them off because they didn't understand, or the confliction of frustration and desperation when he had a big enough fight with his brother to cause them to split, and why couldn't he just understand! There was also the guilt, mixed with shame and topped with absolute grief that came when yet another aquiantance/friend/family died.
This feeling in comparison was no where near as steadily destructive as the others. The feeling of emptiness and disorientation just before you pass out from blood loss. Sure Sam hadn't experienced heaps of times, but in a job like his it had happened enough for him to memorise the feel even being seconds from passing out. Some times Dean made in time to stop the flow and just keep him on the edge of consciousness, a steady haze of pain and a pervading sense of danger that never truly went away even when fully rational. Other times Sam had lost consciousness after staggering away from a fight with vampires or Werwolves or demons or any other being out for his blood, only to wake up and find that - while still lacking blood - he had survived yet another possibly fatal injury.
This time there would be no saving though, or waking up to find that everything was fine once again and Dean was waiting in the Impala to head out to the next hunt.
This time the damn demon had sliced just enough to make the blood impossible to stop for one man. Dean was nowhere in sight and Sam could barely lift a hand to press onto the cuts, let alone call someone for help. There was no saving this time. It figured that he would survive two apocalae, be possessed several times, be revived even more times and then be ganked by a low-level demon in a warehouse that not even rats would stay. Yet another crazy adventure for one Samuel Winchester. Dean was right, he couldn't escape from hunting, it always found away to tear him to shreds (quite literally).
Sam stared at the dust and blood drowned floor, head resting in a lake of his own life and aware of the already familiar feeling of dizziness that warned him he was seconds away from passing out. In his haze-induced state it occurred to him that his hair would be all mattered from the blood he was resting in and that would only give Dean an excuse to cut it's soon as he got there - if he got there. A half chocked on giggle escaped him as he pictured Dean trying to cut the blood on the ground because that's where most of his brother was.
The hand holding one of the gushing wound twitched weakly as Sam attempted and failed to curl in on himself. Blood should not be so hard to move in, it was only a slightly different density to water. But no amount of twitching moved him any closer to the rest of his body.
The feeling by now had swallowed him whole, visions of past events dancing in his peripherals and coldness tearing up his body like a hellhound eager to deliver another soul to hell. Worst of all though was the emptiness. A soul-deep feeling connected to memories of just after Galadriel left his body, or getting Meg exorcised from him so long ago. It may have seemed like a pleasant experience, akin to being back in the drivers seat after having to seat in a foreign place for so long, but in reality there was only the sticky wrongness left behind and the shameful sadness that there was something missing. Something that had become a part of him had been taken away, no matter how bad or wrong it was.
Blood loss was similar, a knowledge that something bad had happened that could not be easily reversed and the missing part that had long been apart of Sam. In this case it was blood, but the had been other times when Sam had wished that there was something with him, an assurance of some kind. Like how blood circled through the blood automatically, it would be nice to sometimes not have to decide - to give up the drivers wheel, so to speak and if it was so wrong, why did it bring relief? Right up until the point where the being in control started killing people. But still, for once the world shouldn't have to be on the shoulders of two human brothers, raised like soldiers and still desperately trying to prove that they were something by throwing away their lives. Even if they were only trying to prove it to each other.
Authors note:
Get it, because Dean is the one driving and he rarely lets Sam drive.
But seriously I could wax poetic on what I think about the Winchester's lives, but I should probably leave at this - for now.