A question about parallel diode configuration
You are plotting the current through R1 the 5 k resistor right ?

And you use an ideal voltage source for testing.

In your current circuit, your "Ampere meter" will NOT be protected because the two diodes can conduct all they want but the current is delivered by an ideal voltage source.

That current source will simply make 10000 Amps flow if that is what it takes to make 9 V. Then 9999.998 Amps will flow through the diode and 2 mA will flow through your 5 k meter.

What you need to do is add some resistance in series with the voltage source. Start with 100 ohms and see how that goes.