Can chanting mantras help me stay calm during unexpected financial or work emergencies?

Hey! My full name is Richa Gupta. I can surely tell you that I was born at 9:05 AM in New Delhi on May 1, 1998. To tell the truth, it is a really long time since my work life has been overwhelmed with a series of emergencies. These situations have not only gone from tight deadlines but also to customer demands and financial problems that have unexpectedly increased. Whenever a crisis appears, I feel as if my heart wants to jump out of my chest, my brain becomes crazy, and I am not able to think. One time a person had suggested that a person should silently repeat the meditation "Om Shanti Om" during a crisis so that the brain will be relaxed. I really want to know if it is true that mantras help under pressure and how I can learn to use them if the stress suddenly comes.