The Dancing On Ice star told The Mirror that it took time for Bobby and Freddy to realise what had happened.
"For 10 months it was almost eerie. It was like they were almost unaffected by it all," he said. "And then we had six months of absolute hell, where I could barely keep up with what was happening.
"It spiralled out of control so quickly. There were more changes in those six months than I've ever had to go through. It was by far the most difficult period of my life."
He continued: "It was chaos. There were extreme amounts of inconsistency and anger from them both because suddenly they didn't know what on earth was going on. They didn't know what they wanted, what they didn't want, what they could have, what they couldn't. It was a little bit of everything.
"There were difficulties at school, not necessarily in bad behaviour but some inappropriate stuff. Outpourings of emotion and talking about Mummy being in heaven when other kids in the class didn't know about those things yet. They were two little boys who were completely lost.
"For all those months they had carried themselves through and it didn't sink in, then it was like they couldn't hide it or forget it anymore," he added. "So the reaction was massively delayed, and huge."
However, Brazier revealed that Bobby and Jack - now seven and six years old - have their own ways of remembering the Big Brother star.
"Thank God, things are a lot calmer now. Now Mum is talked about a lot, and the boys are even talking about her to their friends, which is fantastic progress," he said. "Every now and then if their pals are round to play, they'll ask me to put on YouTube so they can watch footage of their mum.
"Their favourite clip is of when Jade was on Stars in Their Eyes singing the country song 'Rose Garden' by Lynn Anderson. They really enjoy watching that. And they love watching the wedding too because that's one of the last big memories of Jade they have. They can see her on the video, and themselves and I think it's good for them.
"They can finally say, 'Yes my mum isn't here, but this is who she was. I'm proud of her, isn't she lovely?' I'm so pleased because I don't want them to hide this stuff and have issues when they're older," he added.