If you're looking to put the brakes on that, I've used LeechBlock to add a 5-second timer to opening a new HN window (along with other block schedules). The timer even fails if it loses focus, so it really helps slow you down.
so youve got the willpower to do something about it but not enough to just stop doing it?
You'll still open new tabs and go to HN, but you'll be reminded quickly, and every day can be downtime day \o/ (for you, personally)