1995 Ford Taurus Car Sputtering/Shaking Even at Idle

Hello, about a month ago my car would have a really hard time turning over, and when it did have a hard time turning over, it would not run well. (Misfiring/hesitation) so, I replaced all plugs and wires, the fuel filter, PCV valve, the distributor cap, the rotor and the two O2 sensors. Then I changed the TPS, then cleaned the Idle Air Control Valve thoroughly. I sprayed cleaner to test for vacuum leaks, and got nothing. My coil definitely has a spark, I tested with my meter. I am stumped. Now the car shakes as if it is misfiring even at idle, and at cruising speeds. Especially when stopped at a stop sign or light. Please help!