Today is a milestone. I passed the 7-day mark, I survived the weekend... And it was quite easy as well. The key thing for me was: Having things to do. In the past I secluded myself and, maybe unconsiously, kept my weekends open during the day. Today, I went to an interior design exposé (I'm renovating a house), I visited my grandparents, I watched a sporting event with my parents... Anyting that would keep me away from my computer and staying alone in my room. And it worked.
I have had urges though, accompanied by the same rationalising thoughts ('There's nothing wrong with MO once week, it's healthy!') but I remembered that this is just a 14-day experiment and I'm only half-way. If I decide to the once-a-week regime, fine, but right now I'm following a different one.
I'm very happy. Let's see what the work-week brings... :)