My wife (38F) confessed she cheated on me (38M) with one of my closest friends (43M). I feel lost.

tl;dr : Working hard to save our marriage, then wife ****s my best friend and bonds emotionally with him
Wife and I have been married for 13 years, have two daughters (10 and 7) and have been together for 19 years. Like many "old couples" our marriage was slowly going adrift but I though we were still a strong couple with good communication (we had been to a couple conselor to address our issues).
After her confession I feel like I have been betrayed twice. It all started under my roof, during my birthday party, when they apparently hid to kiss. Then they DATED for the last month. In the meantime, I spent quality time with my wife and this exact same friend, held big holiday parties with them (you might want to know that I do not live in my native country so my circle of friends is like my chosen family). I am so ******.
I can't help but thinking I am responsible for that, by neglecting my wife? I am an hyperactive workoholic (university professor, I also co-own a small company and sometimes take contracts as an actor/model). Wife and I (+ counselor) had agreed that we should spend more time together as a couple. Recently, (please don't judge us!!) my wife also suggested that we try opening ourselves to other stuff... like ****ing a stranger, to spice up our "almost dead" couple and wake up our inner pulsions. I agreed (never would I have thought she would be open to something like that, being jealous as hell when I am not home) , but now I understand that she was already seeing the guy, and that he might not be just a "**** friend", because she is probably involved emotionally with him, from what I understood. But at the same time, she confessed me all, because she feels lost.
So guys and gals, help me out. Should I give up on her (them - this guy is figuratively dead to me) ? Should I forgive and go forward to save my family (and pretend that it is just one of the extra-adventures that we allowed ourselves to have) ? Should I just wait and see ?


Source.