I went to a time management workshop years ago and heard a story about a guy who asked his secretary to schedule four fake trips for him per year. He traveled often and had noticed he was always very productive before he left on a trip. He would make those phone calls he had been putting off, finish projects he knew he would not be able to work on while on the road. (this happened in the days before cell phones and portable computers).
Four times a year, she would tell him his trip was coming up, and he'd get a lot off work done. Then four times a year, she would tell him at the last minute that the trip he had scheduled for the next day was not going to happen. He'd been so efficient and productive that he was able to do bigger projects with the time he now had open.
Can you use something similar in your writing life? Is there some way you could fool yourself or get someone else to fool you into being productive with your writing? An artificial deadline that you believe is real? A fake trip? A dinner you thought you were committed to go to but turns out to be a fiction your spouse created to give you an unexpected few hours unscheduled you can use to write?