How can I get my manga notes back?

Hello!
I wrote a bunch of notes in the little section that shows up when you save a story. I wrote them for Blue Lock, a detailed paragraph description for each chapter I read, for about 15 chapters (in the three hundreds). However, not only were all my notes gone, it doesn't even show where I last left off. I used my notes as a way to remember, and I am very disappointed and concerned about this; Blue Lock is such an important manga to me and all my work is gone. If someone knows what to do, that would be great. Any words of advice help.