In the end, you're gonna do what you want anyway, so my advice will probably be meaningless, but here goes...
Most internet relationships don't work out. I've seen it time and time again, and also have fist hand experience with it. I met a guy online, and over a period of 5 years, somewhere along the line we "fell in love". 5 years is a long time, and you think by then you would know someone. We e-mailed, and chatted, and im'd every day, we wrote each other letters (actual written letters) and talked on the phone all the time. Things were wonderful. When we actually met it was a completely different story. I wont go into details, but it just didn't work.
My girlfriend went thru the same thing. Except that she and her internet "boyfriend" talked for 7 years before they met. They were ingaged, and within a few months, realized that they both weren't who the said they were online.
Everything seems so wonderful when you can be whoever you want to be, and no one knows any different. It's easy to say and do the things that you think will impress another person, without actually meaning it, especially when you are not face to face.
I fell really bad for your wife (i'm not saying you are a bad person, this happens to a lot of people... It so easy to get caught up in the moment, and give in to temptations of all kinds... And that "new" "exciting" feeling can be addictive... What i'm saying is that I understand how you got where you are.) think about what your wife is going through right now. She has devoted 10 years of her life to you. And now she finds out that someone else has your heart? It's a womans worst nightmare. This must be devastating for her, and i'm surprised she hasn't left you. (don't take that the wrong way, it wasn't meant to be an insult) i'm just saying that she must really love you to want to work this out, even though you have been emotionally unfaithful.
If you don't love your wife anymore, let her go. Don't string her along. Don't put her through this pain.
Some people were saying on here that you should stay together for your kids. That's wrong. Children are very much in tune to their parents relationship, and they know when something isn't right, and it can be more damaging for them if you stay together. Especially if you are arguing a lot.
Your children will turn out fine in the event of a divorce, but you have to let them know that it's not their fault, and you have to let them know, and feel how much you truly love them. My parents divorced, but all the while, they made sure that me, and my two brothers, knew how much we were loved, and that it wasn't because of us that things between them didn't work out. When my parents saw each other (like trade off time - joint custody) the would say hello, and hug, and be very friendly, so that we would know they didn't hate each other. It's also important not to try to turn your kids against one another...
I hope you make the right decision, whatever that may be. I wish you luck.
Please stop hurting your wife. Make up your mind.
Qriosity