Your story was very good in the first two seasons. It's hard to find stories focused on Demetri, since many authors prefer to write about more popular characters, such as Eli/Hawk, Miguel, Robby, Tory, Sam and Moon. That's why I value your work and believe that it can inspire other writers.
However, I have to be honest: I didn't like the third book. The protagonist was portrayed in a way that made me lose interest in her. Instead of maturing, she became selfish, immature and moody. She seemed to act like a child instead of facing her problems like an adult. What bothered me the most was seeing her join Cobra Kai out of cowardice, instead of seeking real growth.
Also, I didn't like the reconciliation with Andy. He humiliated and cheated the protagonist, and I don't see any point in her going back to someone so toxic. If the goal was to explore a new romance, there would be other better options. Demetri made a mistake, but he was never cruel or manipulative. I don't think it's fair that the protagonist forgives Andy but not Demetri.
I know that many readers may have liked this approach, perhaps because they are younger and don't see these aspects. But, for me, this change in the protagonist was frustrating. That's why I decided not to continue reading your stories.
I hope my comment doesn't affect you negatively. You are very talented, and I hope you continue writing and growing as an author. Don't give up on your dreams!