Yeah, writer's block can be a challenge. I now plan everything in advance which pushes the writers block to the beginning of the project instead of the middle ;)
I find that if I start a project with the theme, and work outwards from there, I tend to minimise writer's block. I guess I try to figure out what I want to say or impart as a writer before I even put pen to paper. If I know what I want to say, then things are a lot easier.
Best of luck with the last five chapters. I love the positive attitude! I'll have to borrow some of that because I tend to panic after I hit publish.