amnesiac,
Congrats on 9 months that is such a great accomplishment. I felt a little irritable and discontent around that timeframe and again at my 1 year birthday.
If you don't want to share it with your sponsor then find another human to share it. I too had some stuff I didn't want to share with my sponsor so I shared with another AA member that has experience sponsoring people.
I have a friend that after doing his 6th and 7th step like the book said. He went for a walk and realized he missed something in his 5th step. While on the walk this inventory item was bothering him. So he passed by a homeless guy and decided to share with this man. He said it was very powerful and relieving experience.
Good luck amnesiac