United Kingdom, May 20 -- Jessica Simpson's "feet were sweating" during her live performance on 'American Idol'.

The 44-year-old pop star performed on TV for the first time in 15 years on 'American Idol', and Jessica has confessed to feeling very nervous ahead of her recent appearance.

The blonde beauty told 'Extra': "Oh, my God, I was dying.

"I can't even tell you how long it's been since I've been that nervous. Like, I had to put hairspray on my feet to stand still, like, not that it actually keeps me put, but, like, my feet were sweating. I'm like, my feet don't sweat.

"I just kept telling myself, 'Do not cry. Do not cry. I know this is a big moment . do not cry.' And then I see my dad, like, up in the corner and I'm like, 'Ah, I'm...