But in real life I don't think this crazy voltage makes sense and goes
What happens in reality that we never see like 10 MegaVolts? Or how
can we model this to make it more realistic?
Your right it's not realistic. If it were realistic you'd be able to generate insanely high voltages. Voltages are limited by how fast electrons can move in a wire after the magnetic field starts to drive them when the inductor is switched.
The main problem is all materials have parasitic resistance an inductance. If you wish to simulate these, then you need to find out what they are for your application. If its a PCB trace, then it has parasitic inductance and resistance, these can be found with PCB trace calculators. If it's a wire, you can look up the wire gauge and find out the inductance per foot and resistance per foot. So the parasitics of the wires connecting components matter in some simulations
Inductors also have parasitic inductance and resistance, these can usually be found in the datasheet. ESR can also be measured with an ohm meter for an approximation for an inductor. In LT spice these are fields that can be modified by right clicking on the inductor.
Everything also has mutual capacitance. Any two metal surfaces have mutual capacitance between them. The wires in an inductor coil also have a small amount of capacitance between them. Below is an example of modeling the parasitics of inductor in fine detail. One thing to realize is the more detailed a model is, the more time it will take to simulate, so go with a more generalized model unless you absolutely have to simulate the details. Models will never reflect what is actually going on in the real world, its your job to know the difference between what the simulation is capable of and what the real world is doing.
Source: Stray capacitance of single-layer solenoid air-core inductors