sagging differentialk/drive axle

My differential mount is broken. The bolt is gone, probably broken out because of rust.

When it broke it caused the rear end to vibrate and make a noise that sounds not good. Now the drive axle and differential are sagging and actually resting on the exhaust.

I was wondering if the mount is replaced and the differential/drive axle reconnected would the vibration stop or is there likely lasting damage as a result of the broken mount?

Also what size is the bolt in the mount?

Any experience is greatly appreciated. Thanks in advance.