2006 Scion Tc base automatic transmission, has 149k miles on it.The car used to vibrate a little at idle. It suddenly started vibrating a lot. It is shaking as if there's an earthquake!

Idle rpm at parking and neutral is close to 1k. Idle vibration goes severe on D and R, at 600-700 rpm. Also, bad smell is coming from exhaust after a while, more like sulfur. The car is shaking so hard that I am not driving it over 25 mph. It is not accelerating either.

Looking for some expert advise. What is exactly wrong with the car?