> "Unfortunately, motivation is fleeting. It's as though my brain is hyper sensitive to novelty"

Not to toot my own horn, but I struggled with this myself and ended up 'inventing' my own psuedo life-philosophy 'Experientialism'[1]. You might find this an interesting way of going about the problem.

[1] https://braunshedd.com/philosophy-and-metaphysics/what-is-ex...