diyanasri,
For my opinion, the inductor impedance looks not to bad.
Try a linear scaling on the frequency axis and you will see a curve that perhaps can satisfy you.
But be aware, that you haven't build an ideal inductor. Thus, there are series and parallel losses which - among other effects - are responsible for the bad high frequency behaviour.
As far as the filter is concerned, I see two buffers (is the 1st one really necessary?) and the inductor.
Where is the capacitor?