Yup, he has, part deliberately, part sub consciously because that's who he is.
Turn your anger outside. Not inside at you. Here are some things that could help. They all come from therapists.
Write you rage down. Then,
Crumple it up, throw it as hard as you can in the bin. If it doesn't go in, throw until it does. If you don't feel any better at all, take it out and re throw. Repeat. And repeat.
Write it down, and then burn. See it turn to ash. Put ash on garden
Write the key words down. Now, with an appropriately coloured pencil, scribble over them as hard as you can. Get rid of as above.
Write the key words down, or more. Put in an envelope. Put in a drawer, bottom of a chest. Close it. It's over.
Weed or dig the garden . Every weed removed, or inch cleared represents something you will never have to go through again.
Get hold of some bulbs and some brown labels with ties. Write the things you want to get out if your system on the labels. Attach them to the bulbs. Dig deep ish holes. Plant the bulbs. Fill in with earth. Nòw stamp HARD on the earth to cover the bulb. Thus will good come from evil. You can also do this with things you hope for. And the DCs might enjòy it too.