It's been a century since I last slept as a vampire. Sleeping through all that time was relatively easy I just closed my eyes and slept, and the time passed. After a century, I woke up, surprisingly aware of exactly how much time had elapsed.
How this happened, and with my feelings somewhat dulled, I ended up just drinking a few bottles of blood and went back to sleep. I slept for at least another 4 centuries.
No one disturbed me during that time. Amazingly, sleeping so much helped more than I expected I was able to adjust and organize all my memories while I slept.
I also managed to discover a way to break Sayuri's curse. In fact, it was so obvious, I'm not sure why I didn't think of it before.
Sayuri's curse works in a 3-phase cycle: a yandere appears, the yandere kills me, I get sent to another world, and it all starts over again. A curse with some pretty simple logic.