You are the last hope of the Time Lords, one of the few remaining pieces of the lost people. She will not win and time will not collapse on itself. She can be defeated right here, right now, without a sacrificing taking place to ensure that. I know everything is converging upon you, and I wish I could take that away, give you some peace from the conflicting timelines and the altering futures. Time will be protected, but you are too important. Perhaps you shouldn't exist, but you do exist. Your parents gave you life, and every life has a meaning and a reason to exist. Yours is not to be a sacrifice. You are to save and protect everything that your father held dear to his heart.
This settles it. If she comes after you or any of us, she's getting a bullet to both of her damned hearts