Lady Gaga has officially launched her long-awaited world tour -- but she admits she once thought she'd never be able to tour again.

On Sunday, the singer took to Twitter to explain how meaningful "The Chromatica Ball" tour -- which opened in Germany over the weekend -- is to her.

"There was a time I thought I’d never be on stage again. I was so sad I couldn’t even dream anything but a painful nightmare," she said. "I’ve overcome my nightmare with love, support, trust, truth, bravery, talent and dedication. I am so grateful."

Gaga later shared her excitement ahead of the opening show, saying on Instagram that she was nervous to tour again after a multi-year pause.

"I feel more clear today than I have in a long time and more pain-free than I have in ages," she said. "Being free of pain, on stage, is a real healing experience because I am able to dance and sing and enjoy the audience and enjoy the show."

Lady Gaga has openly struggled with her mental health, telling fans of her battles with depression, anxiety and PTSD. The Grammy winner was also diagnosed with fibromyalgia, a condition that causes pain all over the body, sleep problems, fatigue and emotional and mental distress, according to the Centers for Disease Control and Prevention.

"To anyone that doesn’t believe in fibromyalgia: I dare you to spend five minutes in my body on a day when I’m in pain, and then try and say it again," she told Variety in 2018 of her diagnosis.

The "Rain on Me" singer's twice-pandemic-delayed "The Chromatica Ball" tour is on its European leg and will be coming to North America on Aug. 6. The multi-date trek wraps Sept. 17 in Miami, Florida.