Tom feels pity -- for himself -- because he accidentally killed Myrtle. He understands that crimes have consequences, but not that other people truly do have pain. ...that's good. Oho that's good.
He has doubts but not enough of them to change his course of action. While I do think that canon TR is a sociopath, this is an interesting take.
Interesting use of the present tense in the middle. I don't know if it was only a typo, but it's a nice take. It's not that Tom didn't want to go back to the orphanage, but that he doesn't. He still doesn't, at the time he's narrating this story, even though he's older and powerful.