I desperately need new brake pads and rotors- As.

Can't tell you that over a computer. How do you know those parts were needed, and how long were you driving since you found out? Lots of city driving or mostly on the highway? Were you hearing grinding noises before this trouble started?

This shaking of which you speak, ... Does that occur while standing still or just when moving? Where do you feel it; steering wheel? Whole car? In the brake pedal?

The shaking is not a brake problem. That's an engine misfire problem. Start with the basics; spark plugs and wires. If your engine uses a distributor, replace the cap and rotor too. Misfires can also be caused by a problem with the fuel injectors, or an engine compression problem related to valves sealing or valve timing.