Bent has joined Fulham on a season-long loan after being frozen out at Villa Park following Lambert's arrival in 2012 even though he was a club-record signing 18 months earlier.
Bent has blasted Lambert since arriving at Craven Cottage, essentially putting a nail in the coffin of his Villa career.
"It was really difficult at Villa because we weren't allowed to play in any matches, a few of us were kind of alienated to train with the kids," Bent said.
"It has been difficult. There were times when I was thinking: 'Do I really deserve this?'
"It's all well and good not being part of the squad, but to be treated like we have is bad. At the same time, I'm trying to put all that behind me.
He added: "It was horrible. It wasn't so much the injuries, although they certainly didn't help, it was just the uncertainty. There were times I was in the squad and times I wasn't and there was just no explanation why.
"I understand that not every player can be every manager's cup of tea, but to be alienated like that, to be kicked out of the first-team dressing-room, when I've played a long time, when I'm an international, just felt a bit disappointing.
"I'm not just hungry to play football again, I'm absolutely starving. I'm ready to get going. Hopefully for the next game I'll get a piece of the action."