Here are three ideas on functioning effectively while under pressure.

1. Avoid the Rabbit Hole: Stop and do a threat assessment. Ignore the “What Ifs” and recall a similar problem you have dealt with. Leverage prior experience to calmly size up the challenge. The key is to deliberately catch yourself, stop, and do this–to not let the pressure send you down that rabbit hole of racing thoughts, which only leads to panic.
2. Reframe the Situation: Emphasize the positive and focus on what you can control. Driving a car, for example, does not faze you (assuming you are a regular driver), because you have control and you have ingrained that confidence into your subconscious mind. A feeling of control makes all the difference. Find that variable of control and use it!
3. Chunk It: The secret to calm and focus is knowing the next step. Ignore thoughts that are not helpful. Make a decision. Focus on the next doable, small step, and you won’t panic. Break the challenge down into its smaller parts, chunk it into those practical units, and systemically conquer it.