I want to add something else that may be important to why these thoughts are in my mind constantly.

Yes the final text was definitely the trigger. Felt robotic and uncaring but also maybe cuz it was final

In one of our last sessions...I brought up how it seemed he didn't care and was unphased by all this. He asked me if I'd feel better if he cried too and I said yes but he didn't

Other than laughing and our chit chat, he was emotionless and unphased the last few sessions. Like when i broke down reading my goodbye letter. He just sat there. Normally he'd say something funny or comforting or hug me. Nothing

His goodbye letter seemed so professional sounding and not personal much at all. It felt like in the end the care was gone.

When we hugged goodbye and I said I would miss him that was the first time he said he'd miss me. I was actually quite ok that evening and he sent a silly text late that night but then the robotic text....and my mind couldn't stop replying how casually he walked away and how unphased he seemed in session

It brought me deep into believing I didn't matter after all and he didn't care anymore etc. Hence where I am now