Buy an electric-assist bike and rediscover the thrills of motion and movement. Remember how good it feels to be riding? You'll get there quicker on an e-bike.
Your past post show you like the mechanical-ness of bikes. On 12-13-20 you posted
"I tend to like bikes not so much for racing pedigree but everyday usability and attractive design."
You can't beat an e-bike for everyday usability.
Or...
Figure out a mod for one of your existing bikes, or find a new project bike that is already ride-able and start wrenching...you'll want to ride it to explore it's new modified personality.
"When the rider is ready, the bike will appear"
Or...find a podcast you may enjoy, put an earbud in ONE ear and go riding...or at least take a walk.
Cycling is like an old familiar tune, once the music starts your body will remember and "sing" along.
The endorphins are out there waiting to flood your mind and body.