I went through this a few years ago, when I was struggling with some physical things as well as career decisions. I've also experienced the regular waxing and waning of my motivation for riding. The thing that helped me during the struggle was trying some "lighter" forms of exercise and trying new things that I thought might help. So, while I didn't ride for a whole fall, I walked outside and I did yoga. A few times, I actually rode to yoga. By the spring, I was riding again, but with no expectation of speed or distance. When summer came, I did a lot of destination rides, like errands, to local farms or the natural foods store. This somehow connected me to things that I hadn't experienced before. I also did most of those rides on my hybrid, not my road bike. My speed was way down, but I didn't care. Last year, I ended up riding less miles than in the past 2 years, I think because the winter had been so warm and I rode through the winter. I did not do this this past winter, and I have a much better attitude.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport