Oh, I knew it!
From the Twice Upon a Time novelisation, these are the Doctor's thoughts as he gets his memories of Clara back: “He wanted to let her inside his head and show her how much of her was in here now. It was like she was dancing through his neurons. The sound of her voice and the things they’d done together were in so many associations, so many connections to other things that he’d been shying away from lately, because they’d seemed so … dull. They had been dull because they had been without her. To see her again was to see hope.”
He definitely chose to regenerate because he was whole again. Clara was missing and now she was back ❤️❤️
I definitely haven't seen anything similar to these ''want her in his mind'' words in AO3 M&E rating works;p
Okay, so it's canon that 12 lived VERY DULL LIFE post-Hell Bent because there's no Clara with him.That he eventually wanted to die.
And i really love the following part of this chapter.
He had been frozen inside, and now these ghosts had given him a chance to thaw. The newly born hope hurt inside him.
Once upon a time, there was a Doctor with bowtie,had been frozen inside,and a Victorian governess had given him a chance thaw.
And twice upon a time.....
