First off, I'm so very sorry you're going through this.
I went through something kind of similar with my wife recently. Married about 5 years, together for 10. Found out about an affair, she lied about how serious it was and we tried to fix it (I really loved her and wanted to make it work). She left me about a month later, and then friends started to tell me about other affairs she had, going back at least 6 years.
This was about 8 months ago.
First, everyone says it, and you don't have to believe it now, but it does get better. For weeks you'll think about it every minute, then you'll find times when 5 minutes go by when you're distracted by other things. Eventually hours. I haven't reached days yet, but I'm hopeful.
Try to eat, try to sleep. I looked like shit for weeks, lost 20 lbs that I didn't have to lose in the first place. I ended up getting a short term prescription for ativan, which was a lifesaver for keeping the anxiety down and letting me sleep. Used it for about 3 months.
Reconnect with old friends. Sometimes they'll say the wrong thing, but they'll save you. They saved me.
Walk or get some exercise when you are able. But don't beat yourself up if you can't do anything for days. I know I couldn't. Sometimes I still can't.
IT DOES GET EASIER. I promise. You'll make it. But that's all I can really say. It sucks. The books don't really help, therapy didn't really help. Nothing really helps. But when you're able, try it all anyways. Back to basics... Don't hurt yourself, eat when you can, sleep when you can, talky to friends when you can, and exercise when you can.
I had to leave town; couldn't do it anymore. Got a new job in a new city across the country. It helped. Sex drive is starting to come back, but I thought I was broken for months.
Please, if it will help, PM me anytime you want. I leaned on people so much, and promised myself I will always try to pay that forward.
If your experience is anything like mine, it's the worst thing you've ever felt. You'll get perspective with time, but that won't help today.
A very dear friend came to help me move out and spent a weekend cooking food to fill my freezer. That was a wonderful help.
Strength and honor.