Speaking English in Panic

How can I overcome speaking English in Panic?
Even though I'v spent almost 1.5 years working as KATUSA, I'm still not used to speak in English, espacially with the upper ranks. Actually I don't really have the barrior with junior soldiers because we talk offen at working, and I'm familar with their voice tone. However, the upper ranks always freak me out. ROKA Soldiers usually have a sense of awe toward the upper ranks. It's kind of showing respectiveness. So am I. For example as I have audience of the commander or the 1SG, I'm afraid to make any mistakes. That's a stressful job. They also understand my feeling so well that they try to speak slowly and be patient.

One day Mrs.SFC, who is notorious as a rapid-fire, whispered me. I didn't catch the point so I asked back, 'Could you say again please?'. However she rushed me to answer it. Before I blame more, let me quick explain the situation. We got the official inspection of maintenace. While a lot of the upper ranks like MAJ, CW4, and MSG came and inspect us, one of them asked one KATUSA soldier about some procedure. When he tried to demonstrae it, he forgot to open the TM, Techical Manual. That's the most important step. At this right time, Mrs.SFC whispered me 'Let him know to pick up the TM and write it down on fifty-nine and eighty-eight'. I was definitely in panic. I know it was a shameful behavior.
If I was quick-witted, I could have given a tip to him. But I failed it. That made Mrs.SFC frustrated. Her frustrated face said me, 'You disappoint me. You're useless'. Finally, I lost confidence. I had a long day.