You need to meet the LoS requirement to get to the boss, which is like 28 or something for the hardest difficulty according to the wiki.
Have you tried 4BB 2CV? (or something like that, I forgot). From what I've heard the night battle node and the node afterwards isn't too much of a pain.As long as you reach 3 ships while counting BB(V)s/CVs/CLTs, you will go to B from the start and then be allowed to take the southern route. (E > H > M)
I started to play Kancolle since January (?) and i still never passed 4-3You must be trolled by the compass maybe. It's known to drive you everywhere else but the boss after the preboss node.... (especially this map, 33% to go to boss or something, since there are 3 possible outcome) Perhaps you're just grinding like Sonata said. If so, you should start trying to seriously go through :p