Therapy and full disclosure

My first meeting with my therapist was better than I expected. She ressured me that nothing I did (or didn't do) would have changed his behavior. She was experienced in not only dealing with sexual abuse, but she had a history of working with sexual offenders as well.

 Having done some research on sexual addiction, I already knew that sexual addiction was progressive (much like drug abuse or alcoholism) and that some sex addicts turn to more taboo behaviors in order to maintain the same "high". She was able to explain this to me further and she told me that often times people who get into legal trouble for acting out behaviors usually have a very long history of acting out, they have often been sexually abused and they're not all necessarily "pedophiles".
 She asked me if I planned to stay with him. This question intrigued me because I thought "what woman would stay?" I asked her, "Wouldn't I be crazy to stay with him?" She told me not at all... there would be hope for recovery if he was willing to do the work, but it would be very difficult and he had to want the help. In addition, I had to be willing to accept the legal ramifications of his actions and the effect that would have on my life not just his.
I had told her about the email he sent explaining that there was more he wanted to be honest about and told her I couldn't go through with hearing that right now. She told me to make a list of all the questions I wanted answered and we could schedule a session with him so that I felt safe and could get some closure, at the very least.
After 6 weeks of ignoring his call and emails I sent him a text that I was ready to hear what he had to say. I told him if he wanted to talk to me he would have to come to my therapist office.
When we met for the session, he informed me that during our entire 2 year relationship while he was supposedly working his side job (a job that did not exist), he was in fact been meeting women, men and transsexuals online for anonymous casual sex. He had also used his side job as his excuse to make time for himself to watch porn and masturbate. There has been a total of 8 individuals he had had sex with and it was sometimes unprotected. He'd been involved in soliciting prostitutes as well as prostituting himself.
Without me asking anything on my list our questions, he answered almost everything. I bawled through the entire session. After he left the room, my therapist sat (shocked herself) and said "wow, I have never seen someone be so upfront and honest".
Her first piece of advice to me was to get tested for all STDs and HIV. This was the first time where I felt that my life might actually be in danger. She told me that my homework assignment would be to get tested before my next visit with her, which I did. Because of the anxiety and the circumstances surrounding getting the test done, during the blood draw I actually had a panic attack and convulsions and had to stay at the doctor's office for over an hour until my panic subsided. The three-day waiting period between taking the test and getting the results was pure hell. I pictured myself getting terrible news and having to tell my family, but luckily everything came back negative.
I still didn't know where I stood with continuing our relationship, but I felt like it took a lot of courage for him to tell me everything had done. After the session he asked if he could walk me to my car. He told me that he knew I hated him and he understood why. I told him I didn't hate him and he broke down. I could see that he was broken and in need of compassion. In all honesty, even though he had spent years lying to me the only thing that saved us was his willingness to come to me and tell me the truth.