gear box

Driving along in my descovery 200 series, then it suddenly stopped going into gear, there is a horrible grinding noise coming from the gearbox and i can only move in fourth gear. When i put my foot on the clutch the noise goes away. I think its the gearbox has thrown a bearing. Do you think this will prob result in me needing a new box. Has anyone else had this problem or have any advice?

Many Thanks.