My wife of 6 years (34F) and who is a family therapist cheated on me. (33M)

We've been together for about 9 years total, we have a daughter (2F) and she's pregnant with a son. To say I'm devastated would be the year's understatement.
To me the real insult is her profession. She works at a behavioral therapy clinic for couples and families. That means she helps people who are having issues in their marriages and families. As you could imagine cheating is a common issue her patients have. Now it turns out she, herself, has been having an affair behind my back. On top of this there were no problems or red flags leading up. I happened purely by accident, not suspicion, to find out (sexual messages lit up the lockscreen on her phone).
I guess to her credit she admitted right away she had hooked up with the guy they were from. This was sometime in the summer. She said he comes to our area for work once a month or so. They met in a bar. He brought her back to his hotel. Etc.
No point in recounting everything in detail, I asked her to leave shortly after I found out, so I could have space to put my thoughts together. But now I feel empty. My family just fell apart, and it's her job to help keep other people's families from doing that.
How do I understand this? She couldn't explain to me why she did it any more than I can to you.
TL;DR: I just found out my wife has been cheating on and off since the summer. It came out of nowhere, she always seemed happy. Don't know what to do.


Source.

Document, divorce, sue for custody and make her ass pay child support

Therapists can be hoes too.