I think he’s a DA, I’m desesperate

My ex (29M) and I were in a long-distance relationship. He has ADHD, which often impacted how he managed stress. Recently, my mother became severely ill, and I had to focus entirely on taking care of her, I was sad and asked often more support on his end. Shortly after this crisis started, right before a weekend we were supposed to spend together, he broke up with me over a phone call.
His reason was that he felt he "couldn't satisfy me," despite me telling him the exact opposite and offering to work through things and repair the relationship. He was completely unyielding, and his final words to me on the call were: "The breakup already started two minutes ago."
To protect my mental health while dealing with my mom’s illness, I immediately blocked his Instagram account. A bit later, he changed his profile from private to public. In a moment of pain and weakness, I unblocked him and checked his stories.
He noticed my views and reacted by blocking my specific account from viewing his stories. Additionally, mutual friends from his social circle, whom I knew prior to the relationship, have recently stopped interacting with my professional social media accounts.
I am struggling to process this. He was the one who firmly decided to end the relationship, so I don't understand why he is actively managing who sees his stories or reacting to my presence. I am already under immense stress due to my mother's health, and trying to decode his final words and these digital actions is draining the little energy I have left. I can’t stop :( seems like OCD.
How can I mentally step away from this and just focus on what matters?