OP, you were stressed and upset for a very good reason so it's not a surprise or something to be ashamed of that you made an irrational decision and drove over the speed limit. Don't wear that mistake as a badge of honour of your love for your mother, but accept it as a mistake and move on. Quit the justifications though, they aren't helping. Nothing you post will make driving at that speed, in your situation, acceptable...because it isn't. It was dangerous, and you weren't saving anyone by getting to the hospital faster.
To the people wondering how people can have no sympathy and be so heartless and unforgiving to the OPs situation, it's not a lack of sympathy. Society shares the road. If someone drove dangerously on their private property I wouldn't give a shit. But doing stuff like what the OP did puts other people in danger...it's not hard to grasp. And no one wants to drive on unsafe, unpredictable roads. If he hit someone, and they die instantly, all of their family members wouldn't get to see them alive again. If you were in the car with your family, and somehow got advance notice that someone was driving 25mph over the speed limit somewhere around you, would you be fine with that? Would you think, "I get it, he can do that, he wants to get to his mom". Or would you think "I'm worried about me and my family's safety"?
http://youtu.be/3qNjt04bpQM
If I were in the court OP I would have been fine with you just getting fined if you accepted you made a mistake under high stress. But you seem so determined that you made the right call I honestly don't think you're a safe driver if you think you can justify those speeds.