Donna Hockey has some good points when it comes to how to keep the writing going. I would add another that she somewhat implied in her title – writing scene to scene.
The is much written out there about writing the beginning of your story: It has to set the scene – introduce the time, the characters, the surroundings; to name just a few, it has to post a question(s) for the reader – a question so good the reader is “hooked” and wants to come back time and time again to find out the answer .
And the end, well, the end sometimes just writes itself, or it’s something easier to figure out than the middle. You don’t hear much about how to write all the stuff in the middle. Yes, there has to be conflict and stumbling blocks for your protagonist to overcome, but what does that mean, exactly!
What I recommend to writers is the write scene by scene. You can make up an outline of the whole story, if you like, if that makes your thoughts flow better, makes you feel more organized, but don’t be surprised if your characters take your story in another directions. Then set the outline aside and start writing. Take the beginning of your story and decide (after the first upset) what your character is going to do next. Just pick something. If you don’t like the direction you character chooses, then cut it later, but for now, just pick something for your character to do, put them in the next place (Alaska, California, their neighborhood park…), with the next set of characters (a flight attendant, a lifeguard, a homeless person…), in the next set of circumstances (trying to escape what just happened to them, trying to find a missing relative, encountering someone who helps push them on one direction or another…). At the end of this scene, something has to have changed, or something has to have happened. It has to propel the character(s) forward in some – maybe small – way, or at minimal is a set-up for something that will happen in the future.
I think the middle is best written this way, scene by scene. I don’t think it feels so daunting this way and if you do as Donna suggests (a very good idea, if it works) and you leave your days writing at a place where you know the character will be next, that will jump start you into your next scene when you again sit down and put pen to paper or finger to keys – whatever your form of poison may be.