ill take a few shots at it, but i would recommend reading the top 3 guides on the SI FORUMS tactics section and then remaking your tactic.
First, playing "very fluid" means that often your players will ignore their individual instructions, folks suggest using fewer differing roles in a very fluid tactic. If you'd like to include all those different roles, i would switch to balanced, or rigid.
6 players on an attack duty means that a majority of your players are making forward runs at any given moment, and nobody is there to support them, so its either a risky forward pass, or lose the ball. Im sure this pays off frequently with the players you have and in a weak (top to bottom) La Liga, especially at home, but, the tactic will fail away from home against the best opposition.
i think two wingbacks on attack duties is too much, especially if you are playing with two CMs, or a single DM. My guess is that you are being beaten on the wings often.
does your main striker ever score? its likely that he isnt getting the ball everyone around him is on an attack duty, so there is nobody looking to spray passes in his direction.
The treq should be on a support duty and so should one of the IFs, you need someone providing through balls to all those players you have on an attack duty. Dont worry, GB or CR7 on a support duty is still going to score you LOADS of goals, their assist numbers should just tick way up.
i would guess that, despite being in first place in february, you give up a ton of goals, even at home?
that is also a staggering number of team instructions. There are a number of changes i would make there, but youd be better off reading those guides i mentioned and tweaking them on your own. I will say that you should take your "allow wide players to switch" shout off. I know they do it in real life, but you want them both to stay where they are as IFs so that they can come in and shoot with their strong foot. Switching them probably jams up the whole thing.
Frankly though, it should be noted that you are in first place in the league, and no matter who you are, it will always be difficult to go to the Nou Camp and get a win. So, take it in stride. Very simply, you are sorely missing a counter tactic, for the few games a year you need it, like this one and if you are enjoying your side and playing well, ignore my advice (other that going to the SI games tactics forum and reading the guides there) and keep having fun.
Personally, I'd rather score 5 and give up 3 than win 2-0 or 1-0 often.