I was diagnosed only a few months ago. I would say I have the same tendencies to a lesser extent. Self-sabotage, in my opinion, could be a direct reflection of our apprehension at doing things we’re not comfortable doing. The overwhelm which many experience with ADHD could be enough to make anyone sabotage things for themselves. However, none of this is our fault. Our brains prefer chaos to stillness.
Another interesting point is many people with ADHD have comorbid disorders along with the condition. One of them is known as ODD(Oppositional Defiant Disorder). In laymen’s terms, any type of authority assigning tasks or being told what to do etc will result in the individual doing the complete opposite. This in a way is a form of self-sabotage. However, so many things can be associated with ADHD, like anxiety disorders, depression, etc.