Dual Resistor in Series with Diode
One way is to estimate the diode as a switch as follows;


for Vd > Vf, Vf=0.6V + Rs ~ 10 Ohms  ( small signal diode )    ( so Vf=0.7 ~ 10mA)     


Rs rises to the leakage value as Vf reduces from 0.6 to 0

So for positive swings, there is no load, Vp=5V    
so I guess  Vp-= -2.5-0.6=-3.1Vp maximum 
and depending on the diode perhaps -2.9V.  


You can compute the incremental Rs of the diode to be 1k and determine Vf at that value to be more precise.