Reborn before the mech apocalypse, I mortgage everything to buy a heavy truck and avenge the traitor

Reborn before the mech apocalypse, I mortgage everything to buy a heavy truck and avenge the traitor Reborn just before the mechanical apocalypse, the protagonist sells his house to buy a heavy truck and stockpile weapons. When the end begins, the truck transforms into a cutting-edge giant mech, letting him slaughter mechanical beasts to grow stronger. With foreknowledge, he seizes rare resources and gear while coldly abandoning those who betrayed him in his past life to the monsters for revenge.