The torn boot caused all of the grease in the joint to drip out and thus causing premature wear on the CV joint. That's what you're hearing when you're turning.
You just need to replace the axle, go to auto zone or something and grab a reman'd axle.
If you drive on it continuously while the joint is like that it will just become really noisy and probably eventually bind up and the wheel on that side won't rotate or turn.