No contact is so difficult when first starting out. You are crafting new pathways in your mind; a better (not bitter ) way of thinking and feeling. All of which is influencing your convictions.
You did perfectly, felt the anger - screw him, I am done, he doesn't deserve my thoughts, he doesn't deserve me - and then let it go. You didn’t act upon it. Very well done indeed.
Feelings are fleeting. Let them flit and find your inner self.
These moments will rise and fall. Each time, when not reinforced, becoming less in amplitude and frequency.
) way of thinking and feeling. All of which is influencing your convictions.