Complice is aimed at exactly this problem. Integrates a bunch of other productivity hacks as well, I love it.
The founder was interviewed on indie hackers recently: https://www.indiehackers.com/businesses/complice
If you want to know if I had a productive day or not ask if I started my day in Complice
It doesn't try to reinvent the productivity wheel, it uses what works. Pomodoros, long term goals, tracking, weekly / monthly reviews, positive reinforcement, optional social accountability.
Plus the guy building it is always adding new things while keeping it familiar.
(Not a lot of people in it lately, but we could change that ;) )
Anyway this post isn't going to give you enough information to recommend anything highly specific, but do you have any ideas what I might have been missing?
Maybe I've just already got that kind of thing well enough sorted, but then, I'm not entirely satisfied with my current approach to self planning.