Driveshaft fell off

New u-joints
Check and balance the drive shaft
Ckeck the yoke to make sure you didn't damage it.

And most important

PAY ATTENTION......When you start feeling a vibration find out what it is and fix it. If you can't diagnose a problem, get on this website and ask. If you had done that last week I can guarantee you that we would have told you to check the u-joints. There's no such thing as a dumb question.

Jim