Stressed out from toxic ex messages - help advice needed

I'm looking for something to help me deal with messages from my angry partner. Therapy is helpful but the nonstop accusations are impacting my mental health.

has anyone heard of withcomposure.com? It looks helpful but I don’t know what it’s about. I heard about it from my attorney.

or any other tools to help? we are court ordered to use ofw but everytime they send an unfounded wild accusation, my first reaction is to get defensive. i know that doesn't work for de-escalating - look this person is trying to push my buttons. other than saying "dont let them get to you" what tools are there out there?