Hey BBB, happy to see you blogging as you're one of my favorite NL players to read hands about.
I can relate in a lot of ways to your post, and hope you wind up not relating to me when it comes to diversification of your assets. I really sht the bed testing that approach ( like wayyyyy bigger than any poker downswing I've had ), and I've found myself in a recovery period accordingly.
Anyhow, maybe I'm off but I'm concerned by the apathetic tone when you're analyzing your disposition at the tables. I think grinding for the sake of grinding can be extremely counterproductive. Also, if you're feeling as though you're unable to find the focus to battle 10k NL, I'm not sure how you're going to give a fk about 500 unless you view it more as a challenge for yourself.
Do you feel you've become complacent or less willing to do hard work that you embraced more when you were hungrier? I found myself in this phase once my finances were good, and I was in a relationship that I wanted at the time. Something I respected about myself prior to all of this was my willingness to suffer, and consistently push through difficult challenges.
A few months ago I tried studying more about how our brain works, why we get complacent, and how to overcome it. I think I hit a good stride for a month and a half until I once again became complacent due to a few factors, with being satisfied with that block of time's results being one of them. I'm looking to sort that out.
Anyhow, sorry for rambling, insinuating, and making this at all about me. All the best, and feel free to reach out if it helps at all to talk. Glgl