Usually under the headers of perfectionism and anxiety. All or nothing thinking, negative thoughts, etc. Lots of people apparently hate the term 'perfectionism' but it fits quite well as the term is used in the field.
Just a quick search but this link probably gives as decent insight into it as any:
Yes, I do feel this way. So much so in fact that I could convince myself that I sleep-typed this, except for the fact that I'm in my mid-thirties. All the way down to gamifying my productivity, racking up points and "indulgences" which I use on junk food, video games, etc. I wish I had an answer, and am keeping an eye out on these replies as well.
That said, all external indicators seem fine. Whenever I bring the issue up to colleagues, superiors, or significant other, they assure me that I work plenty hard. I'm doing "okay" in my line of work, on track for a passable career in research. But I am all too aware of how much time I waste and how much better I could be doing. This troubles me because I know my work makes a difference in the grand scheme of things.
It's possible that we only have so many creative/intense work hours in the day and it's a lot fewer than we realize. In my case, I probably average around 3 hours of solid work per day, highly irregular (most days probably 1-2 with some hard spikes).
Shortly before finishing grad school, I did go see a therapist. He said something like "You might have a mild case of ADD, but you seem to be making it work so far (was finishing up a PhD). I could prescribe you medication, but I wouldn't want to mess with what seems to be working for you." To start with, he recommended the book "The Mindfulness Prescription for ADHD" and the Mindspace app. These were nice, but in my mind they are just thrown into the bin of "things that worked for a little while". Now that I live elsewhere, I've been considering seeing someone again.
I'm starting to just chalk this up to the human condition. Maybe I'm wrong about intelligence and my more successful peers (whom I've seen as equals in innate ability) might actually be brighter, not just more disciplined workers.
I'm looking for "the" magic answer, not because it would be easy, but because I don't want to sink more effort into just another method that may or may not work in the end. In a way, I'm getting demoralized on the subject of self-improvement.
For what it's worth, several years ago during an "enhanced" experience, I had the following realization, which might have some truth to it. Paying so much attention to self-improvement, month after month, year after year, trains your brain to think you're a loser. The constant thoughts of "I'm too lazy, how do I get better" eventually get internalized. This is probably unhealthy and might even be counter-productive.
Though I wouldn't be surprised if the avoidance of work is ultimately an emotional issue.