Regeneration never crossed his mind. He stood before the Daleks, wanting nothing more than to be exterminated. In that one moment he was completely selfish. He wasn't thinking about Martha being trapped in 1930, and the destruction of the human race didn't pang him in the least. He stood before death, willing victim. Hoping in the quiet of his still hearts he might find forgiveness. From who, he knew not. For what, he knew all too well. For every life he never saved. For every stolen moment of happiness he could never deserve. For one planet lost in flame caught by his own hand. For one people turned to ash by his will. But mostly for one shooting star across the sky of humanity. A star too bright to hold on to. A star he'd nearly snuffed out entirely.
He'd played God. If you're looking for a higher authority there isn't one. Bull shit. Because he could name a few off the top of his head. A certain star named Rose Tyler was quick in coming to mind. And maybe... God? Was there a God? Now there was a question he'd avoided answering his entire life. He hated not being in control. And as one final act he chose death over life, peace over war. Silence over the constant, maddening beat of his own hearts.
And then it was over. He came out infuriatingly alive. Guilt still weighing heavily on his conscience. But maybe he didn't want to die. Not that he particularly wanted to continue living. He just didn't want to die, not then at least. And life went back to normal. Not exactly the 9-to-5, but normal is relative.