Turning a PMOS Common Source into a Voltage Follower
You generally make it a voltage follower by taking the output from the source - your output is from the drain. Also your bias arrangement is so far off for what is needed too. By using a P channel MOSFET as a source follower you need to reference the input to the positive rail. This may not be apparent immediately but is important when noise on power rails is considered.

Here's an P channel MOSFET common drain circuit i.e. source follower aka voltage follower: -







simulate this circuit &ndash; Schematic created using CircuitLab

R2 and R3 set the bias point to put the source roughly about half the supply rail. You would inject an AC signal into the gate via a capacitor to avoid upsetting the bias point.

If you are still intent on having your output from the drain then experiment with my circuit by putting a 1k resistor in the drain - keep the 100 ohm in the source though because this will stabilize and linearize the output.