Need help with this voltage regulator circuit simulation

[electrophile]

Hi, I'm trying to build a 12V, 3A voltage regulator. Attached here is the simulation schematic and LTSpice IV libraries for TL431 reference voltage IC. Can you please tell me what is going wrong here? The simulation takes ages. I have a feeling the transient analysis inputs are off but I'm not sure how and what values I should input here for a 5 second plot.

Any help would be appreciated. Thanks.

LM1085-sim.zip

 

[indulis]

Simplify the circuit... remove the OVP (over voltage protection) circuit... then it runs fast If you want to simulate the OVP function, do that by itself.