In the file “sosc2.sp” that you subsequently added to your comment above your diodes have Ron=10Ω and Vfwd=1V, which is again different from your written description.
I am attaching the corresponding PLECS model. It produces very similar results compared to an LTspice simulation of your schematic: 4.2Vpp and 46.5kHz in PLECS compared to 4.1Vpp and 46.2kHz in LTspice.
sosc2.plecs (14.3 KB)