Now my sons talk to me disrespectfully, and accuse me of abusing them when they were little.
And you deny it? That is the issue. They came from an abusive household, one where you were also abused, which means you were screwed up from that abuse when they were young at least, which means you did and said things that you either do not remember, did not believe was abusive, or were so screwed up didn't realize what you were doing. They are both saying it, which means at least in their minds it is/was real, it is shier reality. Denying it, to them, means you are refusing to admit and accept what they perceive you did. Just piles on the BS. Try another tact, if you don't remember then say so, but also apologize, do not defend though. Just comes off as justification. Not sure why you are saying the abuse is repeating, is it they are doing the same to their children or are you talking about the way they talk to you? If it is the disrespect to you, could have everything to do with your response to their accusations.