It will happen to all of you. While writing, you will lose your way, lose your confidence, lose sight of what your story is about, and panic.
If you are using an outline, this is far less likely to happen because you have a plan and know where you are going next.
You can get back on track if you remind yourself that you are writing a novel made up of a main plot and a few to several subplots. And that your story has one focus – the central character, your protagonist.
The central character in each plot will be in a situation of your design (a place, a time, a world) where he will have a driving objective (a goal, want, need, desire).
That goal will move your character to action – in pursuit of that goal. Things happen to him because of what he is pursuing. Don't let him sit idle and have random bad luck happen to him. Put him in motion and keep him in motion.
His actions to pursue his goal will be blocked by a source of conflict – an antagonist.
Your scenes should demonstrate obstacle (conflict) and should raise questions and cause the reader to worry (dramatic tension). Any scene that doesn't do these things needs to be flagged for revision or elimination.
Your character moves forward through the story encountering more and greater obstacles or the same amount of obstacles with less and less in the way of resources to overcome them. Either result in rising story intensity and more worry for your reader — your two primary goals in your story's design.
Eventually, your protagonist will run out of options to attempt to achieve his goal and have one last attempt left. It will appear to him and the reader as a last chance scene. He will either succeed or fail in this scene – the climax – and there will be no further options open to him if he fails.
The climax will answer the dramatic question: Will my character get what he wants/needs/desires, or not?
After this climax occurs, your story will turn to falling action as loose ends are resolved.
And this resolution should only occupy a few pages, at most, because your story has ended, conflict is over, and your reader will sit back and stop worrying.
These recommendations might just help you revise your outline as a guide to what to write next, where your story has been, and where it still needs to go.