Yep, I've had ADHD my whole life. The inability to focus can be a blessing sometimes, but others, it just makes me feel incompetent. This issue has caused me to be socially reclusive, due to me having a hard time not upsetting people. It's also caused me not to be able to keep positive thoughts in order long enough to triumph over the bad ones (which are erratic but persistent). What I do now -- and it can take a while -- is I write down counters to these insults inside my head and recite them later when the negative thoughts are too overwhelming. It has helped me in the past, though not every time. Just takes practice and persistence, I guess.