Hi,
Just to verify that it is a 0.002 Ohm resistor and not a 2M resistor (2M as we usually write 2 megohms) the theoretical calculation comes out to:
Vout=251.327 nV
which matches your plot result closely.
If you had an actual 2 megohm resistor here, it would have came out very very close to 1v.
For reference, the theoretical calculation comes out to:
Vout=(2*pi*f*C*R)/sqrt(4*pi^2*f^2*C^2*R^2+1)
with f, C, and R positive, and pi=3.14159265...