Ambition & Stress are two different things. Don't let your stress capture your brain & creativity. Be determined to the result, success and discover your tenacity, and find your dream job to be simply happy.
I suggest you to read “The End of Stress” by Don Joseph Goewey, which is an important resource to learn more about stress and how it's damaging your mental health.
Here is a quick catch up about the book;
Stress inflicts major harm on your health, intelligence and performance. Luckily, you can overcome the negative influence of stress by incorporating certain exercises into your life and adopting the right mind-set.
Hawaiianize your mind when faced with stressful situations
Think back on a memory that brings you contentment and peace: maybe your honeymoon or the smell of grandma’s freshly baked cookies. Feel how the memory calms you, and relish the experience. Now that you feel calm, you’re better equipped to fully utilize your brain’s higher functions and increase your performance.