SEASON 12 AU. (contains spoilers.)

[neverrefuse]

tl;dr The Timless Child does not exist and the Doctor is a Time Lord from the planet Gallifrey. More specifically, the Timeless Child and all the so-called memories of the Doctor living and dying countless times was fabricated by the Master. He hacked these false memories into the Matrix in order to drive the Doctor over the edge, hopefully into madness. The Master is always going out of his way to drag the Doctor down to his level and this was just his latest elaborate scheme. The Doctor uncovered his scheme by sonicing and hacking her way through the Matrix into the real memory files. While the Master had cleverly overlayed these false memories to look like they were the true ones, they broke down the deeper the Doctor dug. The Doctor is a Time Lord from Gallifrey and has only lived the lives she remembers. She is not some unknown species from an unknown planet. Also, the Time Lords were not created from the Doctor's DNA. Additionally "Ruth" is not an unknown previous incarnation of the Doctor but the current incarnation of the Valeyard. The Valeyard had previously been left on the planet Grahv to live countless centuries believing they were the Doctor and this has continued. Although Grahv was time-locked, the Valeyard has been freed and now travels through time and space with their Tardis. (And because of their belief that they are the Doctor, their Tardis looks like a blue police box). Since the Valeyard is part of the Doctor, they share DNA, leading to the Judoon mistaking the Doctor for being a fugitive. The real fugitive is, of course, the Valeyard. Even though the memories the Doctor experienced in the Matrix were fake, they still felt very real to the Doctor. She felt every one of those deaths and the experience has had a lasting traumatic effect on her.