Welcome back! I’m hoping Beeminder works better for you this time. You’ve made some interesting points so I’m looking forward to seeing how it goes for you.
I also have trouble with leaving goals until too late at night, so I’ve started slowly setting up a waterfall system, which is helping, although I’ve derailed a couple of times from forgetting a goal was due earlier now. 
Are you aware that GTBee is no longer supported and may disappear in future? I’ve been using the excellent TaskRatchet instead - create once-off tasks with a deadline, pay money if you don’t complete them on time. It integrates with Beeminder if you want a goal to ensure you use TaskRatchet regularly.
That resonates with me! One of my biggest problems is getting into such a funk that I can’t do anything productive, and that can last for hours on a bad day. It’s just occurred to me while reading your post that I could have an emergency shell script activated with a keystroke that sends a task to TaskRatchet with a deadline 15 minutes into the future to just do something (maybe make it pick a random task from my list to do just a few minutes wok on). I’m hoping that will change me from a depressed/fearful state into a more productive one. 
So, thank you for the inspiration!