When I was beeminding a job search, which has a lot of similar “this is annoying and hard but necessary to achieve the outcome I want” moments, I counted pomodoros. I ended up being a bit lax about the definition of “pomodoro,” and the end result was something similar to what @adamwolf is suggesting. It meant I had to sit down and dig in long enough to do some real work, but I wasn’t committing to a huge amount overall.
The rate that ended up being sustainable for me was 2 per day (about an hour of real work) - which was consistently less than I felt like I ‘should’ be doing, but consistently more than I would have been able to push myself to do without Beeminder. Obviously wedding planning will proceed at a very different rate, but it’s a good example of the difference it makes to sit down for a block of time vs. do a whole lot of starting and stopping.