
Maybe
Star Split? Society is divided into "Genhants" (genetically enhanced humans) and "Originals." Main character, Darci, is a Genhant fascinated with Originals.
Slake's Limbo Cover has the broken glasses, too.

You're welcome! Happy to help. :)
Possessed by Kate Cann?
"Sixteen-year-old Rayne escapes London, her mother, and boyfriend for a job in the country at Morton's Keep, where she is drawn to a mysterious clique and its leader, St. John, but puzzles over whether the growing evil she senses is from the manor house or her new friends."

Sounds a bit like
Kissing Tennessee: and Other Stories from the Stardust Dance - but I don't remember any specific stories from it...

When were you in high school? Do you remember if the book looked older or new-ish at the time? It will help narrow it down.

The satire and standardized tests make me think of
Story Time

Could you possibly be thinking of
The Name of This Book Is Secret? Green cover, and uses second-person to address the reader. A funny mystery.
Damage is another YA book that uses this narrative style, but it's about a teenage boy dealing with depression, so probably not it. I'll keep thinking.

Hurrah! I'm so glad that's it. Happy Re-reading
But I don't believe this is a YA book, even though it appealed to YA audiences, so I'm going to change this to adult fiction, unless y'all strenuously object.

You're welcome! Janet - is this the one you were thinking of, too?

My local library must not have owned this book when I was a teenager, or I would SO TOTALLY have read it. Congrats on being reunited with your lost book. :)

I can't find much information on this one, except it seems that Ruth is a pie-baking octopus:
Ruth's Bake Shop