My unexpected bombshell

I did a quick google search and came across this site. I'm absolutely devastated about news I received on Monday that my wife, absolutely out of the blue told me that after 18 years that she no longer loves me and said its over. We've 3 kids, 2 boys and a girl in the middle, 4,8&10. I don't know how I can cope with this but my main concern is the kids. My wife who I love with all my heart is mid 30's but since November has been acting like a teenager, out almost every weekend. She is a ridiculously good looking woman and has lost a lot of weight over the last year and is perhaps over confident. Sometimes out till 7am and with her workmates. Where she works it is joked that this place is a marriage breaker but I always laughed it off saying nothing would ever happen us as everyone sees us as being the perfect family. How wrong they and I are! Problems are she told me this news at 2 and left at 3 to tell her parents. I spoke to her sister that evening and she said to her that she was going to let the kids know. I asked her not to and she agreed. But she, I found out today that she has told some of her workmates as soon as yesterday that it was over and as this is a small community I'm afraid that this will filter to the school and indirectly to our kids. But we've got nothing sorted yet and it is much too early to tell them. I'm not prepared and this is going to destroy them. The major problem is at she does shift work so I have always been the one that gets them up and ready for school and some weeks, my mother minds them depending on her shifts. Her family generally has no input. But she so far is adamant that while custody is going to be 50/50 ill be the one to leave. She's obviously looking for the Hollywood life because this just cannot work. And my position is that she has made her bed and she has got to go herself because this is her own making. For what it's worth, without much proof, I'm convinced she's having an affair, more than likely with her boss who is also married but could be with another work mate. I know this sounds paranoid but there are seeds in my mind for the last 6 or so weeks now that I'm putting the pieces together. Again, sorry for ranting here but I don't know who to talk to and if anyone has been in a similar situation who can offer me a bit of advice it would be greatly appreciated and help my broken heart. Thanks (I originally posted this in the separation section but was told to put it here as everyone said she is unfaithful without doubt. So I need to fing out if she is and how to go about it)

Put the internet to work for you. via Personal Recipe 2629979