Whenever your stuck on something or need help, always think of 'practise.' But here's a bit of advice:
Jumping high: Jump normally, and when your about to land/touch the ground, bend your knees, then push out with them quickly and hard. If you know what I'm saying. But don't over-do it, incase you might embarrass yourself into breaking your springs.
Running fast: Run normally, but more carefully until you have the confidence.
And you don't need to release a pack of hungry lions to force yourself.