Numbing the pain for a while will make it worse when you finally feel it.

There is no shame in what you are feeling, Harry,' said Dumbledore's voice. 'On the contrary... the fact that you can feel pain like this is your greatest strength.

O sofrimento é certo e chegará a seu tempo. - Dumbledore

You care so much you feel as though you will bleed to death with the pain of it.

And then a silver hare, a boar, and a fox soared past Harry, Ron, and Hermione's heads: The dementors fell back before the creatures' approach. Three more people had arrived out of the darkness to stand beside them, their wands outstretched, continuing to cast their Patronuses: Luna, Ernie, and Seamus.

"That's right," said Luna encouragingly, as if they were back in the Room of Requirement and this was simply spell practice for the D.A. "That's right, Harry... come on, think of something happy..."

"Something happy?" he said, his voice cracked.

"We're all still here," she whispered, "we're still fighting. Come on, now..."

There was a silver spark, then a wavering light, and then, with the greatest effort it had ever cost him, the stag burst from the end of Harry's wand.

But somebody else had spoken Snape’s name, quite softly.
“Severus . . .”
The sound frightened Harry beyond anything he had experienced all evening. For the first time, Dumbledore was pleading.
Snape gazed for a moment at Dumbledore, and there was revulsion and hatred etched in the harsh lines of his face.
“Severus . . . please . . .”
Snape raised his wand and pointed it directly at Dumbledore.
“Avada Kedavra!”
A jet of green light shot from the end of Snape’s wand and hit Dumbledore squarely in the chest. Harry’s scream of horror never left him; silent and unmoving, he was forced to watch as Dumbledore was blasted into the air. For a split second, he seemed to hang suspended beneath the shining skull, and then he fell slowly backward, like a great rag doll, over the battlements and out of sight.