Your experiences are very similar to mine too, and both myself and my children have moderately severe ADHD. So take that for what it is worth.

Although ADHD use to be broken into inattentive and hyperactive subtypes, current research is finding that the subtypes (as well as the ADD/ADHD label) are not accurate and its all really one condition with variances based on genetics and comorbid traits. ADHD is caused by dopamine uptake inhibition (which is why we have trouble with focusing unless we get really excited about what we are doing, which then we usually hyperfocus. So each person's chemistry and frontal lobe development affects the "type" of ADHD more than anything.

ADHD is caused by an under-developed pre-frontal cortex, which in turn affects our executive functions (such as time management, emotional control, hindsight/foresight, planning & organization, working memory, etc). Every ADHDer has varying degrees of compromised executive functions, so we are all a bit different and some worse than others, but we all share the focus issues from the low dopamine (which is why stimulants work well for most of us).

The other component is comorbid traits (such as OCD, ODD, anxiety, Tourette's, dyslexia, autism, etc). Most ADHDers have on average 2 comoribd traits, and interestingly enough they are inherited (along with the ADHD), so families tend to display the same co-morbidity traits.

Of course, find an psychiatrist or physician who specializes in atypical learning disorders and executive functions and get properly diagnosed. Stay away from primary care (unless they understand the importance of ayptical diagnosis and screening and recommend you to the right person) and nuerotypcial therapies or treatments. They will do more harm than good.

Good luck.