I understand the 'habit' part of it. When I was a teenager, I went through several phases where I kept saying "I'm sorry" to everything that anyone said. I wasn't actually sorry -- it really was more of an automated response. But of course it prompted others to talk about my 'insecurity' and that, in turn, made me insecure. I was, as you said, caught in a loop. I really had to force myself to NOT say it in order to break the habit.

I think your situation is much more complex than mine was, but I thought I'd share that experience.

On the other hand, could you just change your 'tone' when you say "I'm bad"? Instead of saying it in an apologetic way, could you say it in an "oh yeah - I'm BAD!" way? Just as part of the weaning process?