Welcome, Moonbeam! I enjoyed reading your first post. It sounds like we have many common interests--low carb diet, resistance training, eyesight improvement, etc. And, like you, I saw these as separate, unrelated interests before I saw progressive hormesis as a unifying concept that could tie them together--as well as continue to suggest new applications to me. Similarly, I was struggling to bring more focus into my life and resist the downward slide of aging. Well, we can't stop aging, but I think that we can get stronger and improve in many ways at any age.
In reading your post, I notice an underlying theme of "lack of focus"--many interests, unread books, internet browsing, things piling up on the desk. My main suggestion at this point would be to choose one problem or idea and work on that for a few weeks until you see progress. Which thing? At some level it doesn't matter, but I would choose something that bothers you the most or where you think you might see the biggest difference. It should not be an area that is too hard, but not should it be too easy. It needs to be an area where you will experience some difficulty and "stress" to a degree that is borderline uncomfortable, and where you can push yourself repeatedly and in a sustained manner for several weeks. If you can do that, I think you'll experience a level of satisfaction and liberation that you may not have felt for some time. The satisfaction, I think, comes both from the freedom in choosing what you are going to work on, and in seeing and feeling the results. Once that first area is well in hand, perhaps in several weeks, you can pick one or two areas to work on, while sustaining your progress in the first area. But you need to start somewhere, even a very limited area.
If you have difficulty picking an area to work on, here's one more suggestion: pick an area having to do with personal physical or mental capacity. If you start with your health and fitness -- the capacity of your own body and mind -- and work outward to dealing with other people, your house, work, family etc., you will feel the benefits more directly, and move up the curve faster.
That has been my experience over the past few years. I've improved my eyesight, lost 25 pounds, greatly increased my weightlifting ability and general strength, given up caffeine...now working on reducing alcohol intake and preparing for a running relay next weekend. This has left me in better shape to deal with challenges at work and at home. I have many undone things to tackle (e.g. home finances and a cluttered basement storage room, etc.....). But I've found that taking on one challenge at a time has worked for me.
Good luck and look forward to your contributions here!