Normal people don't get fired, or quit just in time to avoid getting fired, from every job. If you're smart enough for the job, then there's something else going on that a psychologist or psychiatrist is well-equipped to handle. Like I said, it's not necessarily ADHD. But it is abnormal behavior and if it makes you unhappy or unfulfilled in this life, then you should do something about it. A good place to start is a mental health professional.