Well, I'm not going to look at porn again, ever, so there's no need to count days there, or have a 'number of days' goal.
And I'm not going to M until my ED is cured, or I die. One or the other. Again, no need for counting the days. It'll happen when it happens....
So I'm not on day 59 of 60, or day 59 of 90. I'm just on day 59.
And all I need to worry about is today. Not tomorrow, not day 90, just today.
Makes it pretty simple. Definitely sustainable.