All of this was a long time coming and some people are put off by how fast everything happened in the episode but psychotic breaks JUST HAPPEN people. You can't plan for them, they sneak up on you.

Haha, I'm so late to this post that it probably doesn't even matter, but I thought that what people really had a problem with wasn't how fast it happened, but rather that there didn't seem to be any sort of trigger for it. It was my understanding that psychotic breaks like the one that Effy had usually have some sort of trigger. Effy didn't seem to have one, though; unless I missed something...?