Factory reset the phone and/or break or dispose of it.
Personally, I'm a private individual and want nobody going through my art and writing and attempting to analyse me by it. They can only misunderstand and insult me by trying. My paracosm is priceless to me, the book of my soul, all I've learned about 'what is or may be' and no other has any right to it, especially not a stranger. I will be taking all my works with me.
As well as removing my phone, I'm removing every data storage device I own. Shutting down and leaving legacy settings on accounts, erasing online data as much as possible. My only record in public will be here.