I must confess to knowing nothing about computers.

我得承认对电脑一窍不通。

《牛津词典》

I must confess something to you.

我必须向你坦白一些事情。

youdao

I must confess that if I had been in the young lady's place, I would, at least, have swept the hearth and wiped the tables with a duster.

我必须承认，如果我处在这位年轻的小姐的位置上，至少，我会打扫壁炉，用个鸡毛帚掸掸桌子。

youdao

First of all I must confess, I do trade.

FORBES: The Great Apple Trade?

After the Friday morning GDP report, I must confess that I may have been wrong about that.

FORBES: The FOMC's Recent Transparency Moves: Worse Than Expected

Back in March, 2011 when I had the idea to start Opportunity Works, Inc. a staffing company with a focus on placing people with disabilities in the workforce, I must confess, my idea was not to start a company at all.

FORBES: Trends In Employing People With Disabilities