This is just a short one shot of what happened to Donna when the Doctor took away her memory.
I actually cried, writing this (though in sure it was only the video that I watched right then). Anyway, enjoy it.

She could not hide what was happening to her. She could not pretend everything was alright. It hurt badly, and she had to steady herself, not looking at him. Donna knew exactly that he was watching her, she could not gave into her weakness.

"Do you know what's happening?"

The words were so clear in her mind despite the flood of information and pictures that consumed her mind. She was dying. And there was nothing she could do.

"Yeah."

"There's never been a human Time Lord metacrisis before now. And you know why."

Why did the Doctor have to do this to her? Why did he have to confront her? She knew what was happening, she accepted it. It was his metacrisis that was killing her, but she was accepting it. All of it.

"Because there can't be. I want to stay."

But Donna could not accept what he was trying to talk her into. Her decision was made long ago. Her future was with this man. The man with the blue box, traveling among the stars, and seeing worlds that no human had seen before. That was everything she wanted. Everything she ever wanted, even though she did not know it her whole life.

"Look at me. Donna, look at me."

Everything inside of her screamed No. Looking at him meant considering it at least in some ways. But looking at him also meant he would see her desperation. The Doctor could not do this to her. He could not leave her.

"I was going to be with you forever."

"I know."

But he didn't. How could he? Her life was nothing without all of this. This was her life. It was supposed to be this way. Forever. The emotions fought inside her, tears shimmering in her eyes as she looked into the Doctors eyes. Though he sounded calm and tried to keep a neutral face, she saw the pain within him as well. And it destroyed her even more.

"The rest of my life, travelling in the Tardis. The Doctor Donna. No. Oh my god. I can't go back. Don't make me go back. Doctor, please, please don't make me go back."

It took her seconds to realize what he was going to do to her. But he couldn't! No, she could not let him do this, she could not go back. Her life would be nothing. She needed him. To die and knowing what lies in the universe, what adventures life had to offer, was a better choice than forgetting him and everything she had seen and living her life as if none of this ever happened.

"Donna. Oh, Donna Noble. I am so sorry. But we had the best of times."

"No."

He had placed his hands on either side of her head, and she could feel it happening. And there was nothing she could do. The tears spilled from her eyes, covered her face, as she saw everything they had been through in mere seconds. Donna saw it all: their first meeting, the second one, the Oods, Agatha Christie, Pompeii, Jenny, the Daleks, and last him disappearing after their first encounter, leaving her in the snow. Oh it hurt so much. So very much. She wouldn't remember anything of it and it killed her this very moment.

"The best. Goodbye."

"No, no, no. Please. Please. No. No."

Don't do this to me! Don't! I'd rather die!, she wanted to scream, but their minds melted completely and everything that had been in front of her eyes seconds ago was ripped away from her. Darkness took place where the moments had been. Everything vanished, like colors in the rain. And at last, the picture of the Doctor's face faded and left her completely. Forever.

"No!"

Her world went black, and she fell. Whatever happened next was unknown to her and she would never ever know about it again.

The next time she woke up again, she was in her room, in her bed. Fully clothed. Something that had happened last when she was a child. It just have been a rough day and night. But what actually happened? There were several calls and messages on her mobile as she looked at the screen and she started to go through them. And what they told her was hilarious. Impossible!

When she went down, she looked at her mobile calling out for her mother and telling about the hilarious imagination of her friend. Not really noticing the man that obviously had never been there before - she would remember such a face, right? - she only greeted him briefly before continuing talking to her mother.

"I was about to leave, so..." The Doctor said and Donna only waved him a quick goodbye before calling her friend.

When the door closed, she stopped in her tracks. She could not say what it was but it was as if she knew that man. But that could not be. Shaking her head, she continue the conversation, not hearing her own faint voice deep inside her mind, speaking to the Doctor that would never hear it.

"Goodbye, my Doctor. I could never forget you."