Snapedom

For someone who is working as a double or triple agent, death and torture would be obvious fears, especially considering how Voldemort treats traitors. However, rather than death per se, I believe that his greatest fear is probably dying before he is able to fulfill the promise he made to Dumbledore on Lily's behalf, of protecting Harry and defeating Voldemort--or of failing in that task, whether he survives or not. In canon, we know that fear was realized when he was slain by Nagini before he could see the outcome of the final battle. Maybe he at least had some hope at the end, knowing that he was passing along those vital memories to Harry.

On the other hand, by that time Snape knew that Dumbledore expected Harry to die along with Voldemort, so maybe his greatest fear and despair was that Lily's son would have to be sacrificed no matter which side won, and knowing that all the work he'd put into protecting Harry over the years would be for naught. Maybe in a grim way, he found some comfort in not having to witness what he believed would be Harry's inevitable death.

Which is not to say that Snape did not fear torture and death at all--I am sure he did, even if it was not what he feared most. But I believe that he accepted that fear and risk as a necessary part of his duties. Neither do I think that bravery is the absence of fear--rather, it takes more bravery to do what one feels is right in spite of one's fears. I remember reading an essay about Superman and bravery years ago--I believe that it was written by a science fiction author; I have a vague recollection that it might be Spider Robinson, but I can't find confirmation of that. Anyway, whoever it was argued that Superman could not be brave because nothing on Earth can physically harm him: he can be good and noble and kind, but not brave in the way that normal people like you and I can be when we act in spite of our fears. Actually, I disagree with the author--Superman may not fear any physical harm other than Kryptonite, but he can certainly fear having the people that he cares about being threatened or killed because of their connection to him. Still, I understand what the author of the essay was trying to say, and I would argue that Snape shows this sort of bravery, in carrying out a difficult task despite the threat of physical harm, as well as all the emotional conflicts and fears that he has to deal with as well.

Another fear Snape shows in the books is for the state of his soul. When Dumbledore asks Snape to kill him so that Draco's soul will not be damaged, Snape retorts, "And my soul, Dumbledore? Mine?" I know we've talked about this before in other essays or discussion posts on Snapedom, that this probably indicates that Snape has never killed anyone before, at least not directly, even as a Death Eater.

And I think that he might fear dying with everyone still believing he is a traitor, with no one knowing his true loyalties. I don't think that he necessarily wants the motivation for his loyalty to Dumbledore to be known, since he insists on keeping it a secret from Harry, but he does react very strongly when Harry calls him a coward at the end of HBP. It's natural for him to feel angry, of course, since he's sacrificed so much to protect Harry, and Harry hasn't a clue, but Snape has such a strong emotional response that I think it's more than that. If he truly didn't care what anyone thought of him, it wouldn't bother him nearly as much. Snape's last dying plea of, "Look...at...me..." could merely be a last wish to look into Lily's eyes, or it could be a plea for Harry, for someone, to look and see the true man within for once.