Kudos to you for sticking by her side and not leaving! It takes a hell of a man (or woman) to not leave a depressed partner.

You say, "There is one thing though that is making it really difficult and that is that she has been speaking to another guy at work." This one thing is a very BIG thing, IMHO. I have MDD/GAD and when I'm having a meltdown either a big one or small one I tell my fiance; I don't even feel comfortable talking to another man about my illness. I'm not ashamed, I just don't want to engage by telling another man I'm two fries short of a Happy Meal. Plus you should be the one she confides in period.

From what you wrote sounds like she doesn't give two s***s about how you or the family feel about the problem. I mean that's crazy for her saying she's not going to cut him off. Like I said I'm depressed too but if I was in her shoes I'd get rid of the dude, no excuses. Just because she's depressed isn't a get out of jail free card for having an emotional affair; yes emotional affair because she's seeking attention from another man that isn't you unfortunately.

Are you both in marriage counseling and/or individual counseling? You sound like a good guy and again I applaud you for sticking by her side, but don't you think things need to change? And if she keeps getting drunk while being on meds it's not going to help at all! Good luck!

Hope this sound like a platitude, but can you go out, perhaps spend a weekend together, get away, try to enjoy some things she might like.

you staying with her is really admirable, but i know when i was really really depressed i was with other people including my boyfriend and thankfully he was understanding. it was a really rough period in our relationship, but after i got treatment for my depression i stopped seeing other people and our relationship improved. i hope you and your wife can get through this. i know how hard it can be but only you can decide if staying with her is right for you. i know most people with depression can appreciate and need as much support as they can get. good luck to you two!

Go visit this workmate and tell him to stop texting your wife or you'll talk to his line manager. I probably wouldn't speak all that quietly when I did that. I might even say it at his workplace.

Fucking with a mentally ill woman is hardly gentlemanly. Fucking with some other guy's mentally ill wife less so.

Otherwise tell the wife she needs to pick a team. And she does. CBT may not be helping her think rationally though, which I am guessing is why you can't really lay down the law with her. But you certainly can lay it down with him.

Do you have gorillagrammes where you live? People that show up at someone's workplace in a gorilla suit and a stereo playing a message, and do a little dance? You could write a witty little poem couldn't you?

Wow thanks for all the comments, it feels good being able to share the situation with impartial people who won’t judge. This guy she speaks to doesn’t know the extent of her sadness, he just thinks she is unhappy in her relationship. If I exposed that to him I fear it would push her away from me. She has such a low self esteem and I suspect he is like an addictive drug. When I try and build her confidence up she just rejects it because I know her state of mind. She insists it is only an emotional affair not physical (still not ok I know). I know deep down this person isnt my wife as she has been so critical of people in her situation in the past. She just can’t seem to stop craving his attention and I suspect that is dragging her self esteem down further with guilt.
I have my first counselling session tomorrow so I’m hoping to get some professional advice that helps tomorrow. In a normal situation I would be laying down the law, she has just got scarily erratic when me and her family have done that and I’m putting her safety before our relationship at the minute. I don’t know how long I can keep it up for as I feel accepting/living with her behaviour will only let it continue.

I find this article summarises it all perfectly

https://www.mentalhelp.net/blogs/when-a-depressed-partner-falls-out-of-love/

Her coworker makes her feel good about herself. If she had a person that was already in her life fill in that space that he takes up she may fall back in love with that person.
Not in any way saying this is your fault. However this person is meeting her emotional needs. Until you do she will fall in love with the other guy.
Look up “emotional needs”
Good luck

"when drunk"

Not sure who gets drunk, but alcohol and mental problems do NOT go well together.

Hello, sorry for the situation. I was put on a medication topamax. Every side affect that this drug have, I was suffering with. One of the side effects was suicide. My friend took the bullets out of the gun, thank GOD. When that was not an option, I went to the Emergency dept and pleated for help. The medication they gave me had no affect of my symptoms. I pleaded with them, I can’ take this ANYMORE. The emergency dept, let me go.. I then went to my Church and the pastor prayed over me. I was planning to end my life that evening. I was planning to take an overdose of medication that evening. My friend talked to me for a long time and made feel better of myself. He said if I committed suicide where would that leave him. I know he cares for me Maybe loves me. He stayed with me, side by side to watch over me. After about 2 weeks he felt safe to leave me alone. The medication took a couple of weeks to get out of my system. I would never do something like that. You need to find all medication, and put it where she cannot find it. Firearms too. Take the bullets out, hide them. Suicide is nothing to take lightly! Hope this helps. Carol anne