I'm also approaching the anniversary of when my panic attacks got so bad that I had to drop out of high school. Come the end of this month, I'll have been out of school for as long as I was in school, which feels very, very strange given that I feel like I could blink and be fifteen again.
Time has always felt odd to me. When I was Jane's age in Book Two, I felt like I was an adult trapped in a child's body. Now, as an adult with a very sheltered, small, panic-ridden life, I feel like a child, or at least, a teenager. Either way, I've always felt out of touch with people my own age. Always felt both ahead and behind. (But now, mostly behind.)
There's no moral to this story. I don't have any grand advice or meaning for you to absorb. But I feel for you if you have some anniversary you're grieving right now. Even if it's just a year of quarantine. That's plenty to grieve on its own.