Whoa that sounds awful! And that's a really harsh thing your mom said to you, considering that you're 9.
You shouldn't have tried to crack your moms password, that clearly was going to make her mad. There could been a virus on her computer, that's probably what changed her profile
Maybe instead of asking your parents and trying to explain what you did wrong, apologize instead, even if you did nothing. They'll probably feel kinda bad about it.
And please don't kill yourself! There's a lot in life you should live for!