[cdent]

A thing to keep in mind is that work (at least as it is commonly practised) is not "normal". It's a thing we have accepted as normal, and if you want to be successful (by the common definitions) then, sure, you need to find some strategies achieve some focus and the ability to bring things to completion. There are plenty of good strategies throughout this thread; exercise and meditation are probably the most important.

But you shouldn't feel like a failure or consider yourself aberrant in some way. You're not built for the way we live now. If you're concerned about ADHD, find a doctor. I know plenty of people who have become much more satisfied with their existence after working through that, figuring out ways to adjust their behaviours.

In the end, you need to balance the utility of coping with the expectations of the modern world (and your own requirements for a comfortable life) against an understanding that the way we live now is messed up.