Wife wants continue enm to cure her depression because she gets the thrill of sleeping with a stranger, I'm torn about what to do?

My wife and I started enm 6 months ago and she hit it off a guy almost instantly.

For almost two years prior to this she was suffering from insomnia and hasn't worked at all or had the motivation to find a job. She spends all day at home and this may have contributed to her depression. 

Unfortunately this new guy was a walking red flag who lied about his age, his martial status and and even his name. When my wife caught whiff of his lies about his age, she asked me to go find out what else he was lying about.

Coming from a cyber security background this was a piece of cake for me, this guy didn't cover his digital footprint accurately and I found out everything including the fact he was a married guy with a kid who did this enm stuff when he was overseas. But he claimed to be a single guy  looking for a casual relationship.

When my wife found out all this she - to my big surprise - dismissed everything as "that's what men do" and since, I had also lied to my friends in the past I shouldn't judge him because he was still a religious man. 

A few days later I was just casually browsing this guy's socials and I was baffled by how many fake accounts he was using to seduce women into thinking he was a single.

I brought this to my wife because it was time she ended things with him.
When she discovered that he was a playboy she furious that I was still digging dirt on him and said he was a much better man than I ever was and was jealous of all the girls and money he had.
She went into a fit of rage - first time ever in our marriage -  and hit me physically.

The next morning she said she was going through a depression for the past year and enm gave her a new purpose in life, it distracted her from having no job and no savings. She wants to go back on feeld and sleep with guys to forget her depression. Her exact words "the thrill of sleeping with strangers makes me forget my problems"

So here I am today, we're currently living separately because the whole thing has traumatized me. I'm torn between getting a divorce or excusing her behavior as someone unable to think properly. But I've also realized non-monogamy is not for me nor for her. She's unable to love two people at the same time.

AITA for exposing to my unemployed wife that her boyfriend is a lying cheater, leading to her hitting me?