Update: I told his sister about my concerns about him likely suffering from depression and anxiety. I told her numerous specifics to back up my statement. She told me that she and her sister have both suffered from depression as well. She was very supportive and we parted ways. A day or two later I emailed my ex DSO about what I had done. It was an email written from my heart. I realized he would think I had betrayed him, and that killed me inside, but I knew I had to do it for his sake. Anyway, he didn't reply back to the email. His sister later told me that she had talked to him and that he wasn't thrilled about her knowing. I then got a very formal email from him regarding some separate business that was signed with his first and last name (I am doubtful it was auto-sign). It definitely hurts that he is being so cruel about it, but at the same time it has helped me with the healing process.