Could I please recommend a book called The Colour Monster? Or even just the premise of it?
DS struggles with anxiety, and finds it hard to explain exactly how he is feeling. This book gives feelings colours (red - angry, happy-yellow etc)
We read it at the start of the week together, and come up with colours for feelings the book doesn't cover.
Since then, I've gotten more out of him this week than in the last few months. Just in case anyone else is going through it, thought I'd share.