I don't think he ever intended to survive. He never cared what people thought, I have a feeling he probably preferred being hated than loved. The only way to clear his name would be to show the entire magical world his deep dark secret and I know he is far too proud to ever accept pity from anyone. It's the reason he's never ever told anyone else how much he loved Lily (besides Dumbledore which was necessary), it's the reason he was only willing to show Harry as he was dying. I don't think he could stand being celebrated like a hero, maybe because he didn't think he was one? I'm sure he'd prefer this quiet reverence people have for him over something like how they treat Harry.

He must have only lived to protect Harry and once he knew Harry would win, there wasn't any point to his life anymore. I think he was far more at peace as he was dying looking into Lily's eyes through Harry than he'd ever been before in his life.

How tragic! Wow I feel like tearing up!

I believe that Snape wanted to die when his childhood love/friend Lilly Potter died but he continued to live to protect her only son, a reminder of Lilly that Snape held onto...

so in some ways did snape want to die after his task was accomplished? and he let nagini bite him? i dont think snape let nagini bite him, i think snape would have preferred to fight out in the open and die with honour and respect he deserved.

but i do believe when he saw harry after nagini bite him and snape was on his deathbed and he passed his knowledge to harry, his mission was accomplished, then yeah he did feel a sense of finality and he died knowing he had achieved his life long goal: protect his childhood friend's son.

I think that Snape probably always knew that he was going to die eventually - he lived a life towards the end so full of danger that how could he hope to survive? But the idea that he wanted to die because Lily was dead is incredibly sad and touching to me, but probably true - he fulfilled what he wanted to do, he passed on the information that was intended for harry, but the problem is, Snape thought he was sending Harry to his death. How could he have been satisfied with dying, when the only reason he was still alive (probably) was to protect Lily's son? Also, I think that Snape could have fought with Voldemort if he had tried, he had a wand, and he was probably nearly as skilled as Voldemort. So why didnt he try to defend himself, when his task of protecting Harry wasn't complete?