The actress-and-singer - who plays Mercedes Jones in the hit musical drama series - was grateful for the support of her co-stars when she performed in front of Barack Obama last year, but admits their reaction didn't calm her nerves.
She said: "My most memorable experience of the past year is singing for President Barack Obama and his family last April at the Annual White House Easter Egg Roll. It will always stay with me.
"The entire 'Glee' cast were there - they told me to look at them if I felt nervous, and I remember looking down from the balcony, seeing 10,000 people, then seeing them and they were all crying. I just thought 'That's not helping!'"
Amber, 24, was also paranoid she would forget the words to the US national anthem after she was told she would have to stand close to the statesman, his wife Michelle and their daughters Malia, 12, and nine-year-old Sasha when she performed.
She explained to Britain's Glamour magazine: "I knew for a while that I was singing the national anthem in front of the President, but I didn't find out until the day before that I was singing it on the White House balcony with First Family sitting next to me!
"I kept repeating in my head, 'Don't forget the words.'"