Wow, so many possible causes for poor concentration! I like this thread as an exagesis.

What works for me is I think also the lowest hanging fruit: a combination of working on things I care about, and actively bringing my wayward bad habits under control.

A reset requires a change of scene. It's likely that you don't like what you do now. That's the root of the problem. Chop it down. Go find something else to do.

Once you pick something, do it all the time. It's analogous to shocking your system with a new diet. Everytime in the past that you procrastinated, you gave strength to these demons. Now it's time to starve them completely for a while.

Get better.