You might be happy to know that the problem you're describing is something I've had happen to me several times in the past. In fact, I started writing chapter 8 of Bully about two months ago, long before Thanksgiving, but I haven't been able to finish it because it just didn't work right for me. Part of that has been because with Bully I didn't flesh out a story line beforehand. Even if I don't put it down on paper, I usually 'imagine out' the story progression in my head before I sit down and write more than one chapter. This helps me keep the flow of the story, and even if I add or subtract major things, I know where I'm working towards and roughly the steps I have to take to get there.

Sometimes I get impatient to reach the end, and try to leave out things I believe are just 'filler'. Yet, most of the time it is those 'filler' things that readers tell me they enjoy the most. In many ways they are absolutely correct, because it is the filler stuff that gives the characters more flesh, more reality. I mean, what does it matter if our main character hates cheese when he's going to be saving the world at the end of the story? Still, the fact that the main character hates cheese is one of those neat little items that make the character more real for most readers, and helps then 'connect' with the character easier as well.

When looked at from that way, these things tend to go from being 'filler' to being vital parts of the story we are telling.