The 'On The Floor' singer announced her separation from her husband of seven years on Friday, prompting reports that she had grown tired of his behaviour.
Sources have since claimed that Lopez "fought" to save her marriage, enduring Anthony's "antagonising" behaviour and attempts to rule their lives.
"She tried so hard to make this marriage work," an insider told E!. "She put up with - and kept putting up with - Marc's controlling ways, which had been going on for a long time, and she was really trying to make the best of it.
"He would micromanage their lives together. He was all over her all the time and I know she tried very hard, and for a long time, to act like it didn't bother her, but I know it did. A lot.
"He would hover over her, and it was almost antagonising," they added. "She couldn't breathe."
Lopez was further described as having put on a brave face during her time on American Idol, despite the problems in her marriage.
Revealing the 41-year-old's "scary" devotion to Anthony backstage, a show source said: "She was always saying, 'Marc likes this' or 'Marc doesn't like that,' as if he was her manager. We never once saw them fight."
Lopez is said to be "devastated" by her divorce from Anthony, having "exhausted all the possibilities" of keeping their marriage together.
The former couple have confirmed that they will continue working together on their upcoming reality show ¡Q'viva! The Chosen and honour their fashion contracts with Kohls department stores.
Lopez was today alleged to have had an affair with male model William Levy, who appeared in her 'I'm Into You' video.
However, his spokesperson insisted to The Sun: "The only relationship there was or is [with Lopez], is a professional relationship."
Watch the video for Jennifer Lopez's 'I'm Into You' below.