I found Newport's book to be so surface level for anyone with even a passing familiarity with the problem that it wasn't worth my time.

What really helped me was these two books:

(1) The Attention Merchants by Tim Wu (2) The Age of Surveillance Capitalism by Shoshanna Zuboff

and the nextdns.io installed on all my devices. I literally blocked Reddit, et al to break the cycle of "I just woke up so I'mm scroll until I'm fully awake" and then oops -- an hour went by.

The thing that ended up motivating me to change was reinforcing for myself the fact that I'm in this mess because very smart people have designed systems to exploit me. Fuck that. I'm in control of my attention.