Every break-up needs time to heal. You're probably angry for a bunch of reasons. But IMHO that healing process can't begin until the stimulus is no longer there. Each time there is an interaction, it stimulates the anger. As long as his number is on your phone, the stimulus is there. Block the number and begin to heal. At least that's how it has been for me. I couldn't start healing until I made active steps to put him out of my current reality. In your case, it sounds like texting = toxic to your calm.