Britney Spears felt "alienated from the public" when she went through a tough time in her life.
The 32-year-old pop star - who exhibited erratic behaviour, including shaving her head, between 2007 and 2008 and was placed under a conservatorship - has recalled feeling so harangued by paparazzi photographers, who would follow her every move, she didn't want to leave her house for nearly two years.
In a candid new documentary 'I Am Britney Jean', which aired on US TV last night (22.12.13), Britney said she felt "alienated" from her fans during the "trying time".
She added: "But as time passed, they lightened up and they went away after I wouldn't come out of the house for two years.
"It was a trying time. It was kind of confusing for me. Personally, I'm a shy person and I'm particularly not really made for this industry because I am so shy. It's not something I deal with so well."
The 'Work Bitch' singer, who is due to begin a two-year residency titled 'Britney: Piece of Me' at Planet Hollywood in Las Vegas on Friday (27.12.13), also spoke of her struggles dealing with pressure, admitting she tends to keep her issues to herself.
Britney explained: "Pressure is a funny thing. Sometimes I tend to go inward when I'm under pressure. I tend to keep it all in. I don't express myself too much. If I'm really nervous I'm really quiet. But I think I thrive under pressure."
The blonde beauty also reveals that she doesn't want any presents for Christmas.
Britney, who has two sons, Sean Preston, eight, and Jayden, seven, with her ex-husband, Kevin Federline, claims there is nothing on her wish list because she is "so happy."
The 'Perfume' hitmaker told EOnline.com: "What do I want Santa to bring me? -- I have everything. I'm so happy. I don't need anything. I just want good health, happiness and love."
However, she admits her children hope to find lots of gifts under the tree.
She said: "They want everything under the sun - iPad Minis, new phones. They act like they're 27 years old. You're eight and seven years old, you can't have an iPad Mini and a phone! They're into gadgets right now. They're into games, computers and all electronic things."
Britney isn't stressed out about shopping for presents because her boyfriend, David Lucado, is not difficult to buy for.
She said: "David is really easy going. If I just got him a card, he'd be really happy, something simple like that."
But she added: "You always make time to go shopping. Always."