Rubicon

...do not rush for clutch and brake!!!

Fight your instinct of rushing for clutch and brake. Do nothing. Just let the engine die.
You are much safer that way.
As long as there is a "solid connection" between your engine, all those other moving parts involved, and your tires your car will sit assolid as a rock. It will not move.

The clutch is the only breaker in that connection. As soon as you step on it your vehicle might move. Now you are thinking, "I will simply hold the car with the brakes". Good thought. But once your engine dies, your power brakes do not work any longer. It will be almost impossible to hold a heavy truck, especially on steeper sites. Your life might be in danger.
So, let your engine die. Take a deep breath. Start thinking of what to do next. And take your time doing so. Rushing will only get you into more trouble. As always in life.

If you decide to continue in the direction you were traveling you will need to start in gear and everything will be good.

If you decide to change directions you will have to change gears with the engine off. Here is how to do that.