There have been many painful moments, and many of them have been mentioned, one that hasn't been said here is one that for me characterised those two painful seasons after the CL victory.
Barca went into the second leg of the Copa del Rey final wiht a commanding victory in the first leg, including a brilliant Messi goal. Jorquera played in goal, I remember him wearing his red GK kit. We conceded 4, against all odds. Just 3 days later, we were up 1-0 against Betis. But I felt that something was wrong, we were very shaky in defence. I'm fairly sure it was Rafael Sobis who was subbed on, around the 60th or so minute, and I knew this was going to go wrong. We'd put in some crap performances against Betis in seasons past. Near the very end of the match Betis got a free kick and Sobis scored. It was so going to happen. It was the point of no return because we lost our title then. Those 3 days, they really encapsulated the way something was inherently wrong with the team after the CL win. I'm not sure if I recall the details correctly but that's the way I remember it to be at least.