Should I Stay Or Should I Go?

I have been with my husband for 10 years, but married for 5. We have two children, a 3 year old girl and a 9 month old son. I thought I had a normal marriage. We had our occasional fights after the kids were born, but overall we were happy. When we did fight it was about how much my husband worked and how much I missed him, problems managing his pain of a mother who constantly butt in (even though we both agreed she was a royal pain) and I was struggling a little with our daughter. Anyway 2 months ago my husband was working late and I went out to give him a kiss goodnight and he quickly turned off the computer. This made me feel taken aback, was he hiding something from me? He denied things and I let it go, then three weeks ago I thought I'd ask him to check his e-mail to put my mind to rest. Well, I found four different sessions of chat with a woman. They had been having video sex and their sex chat was still on his account. What was worse it was while I was in hospital with our son. He intially told me it was just online and finished after 3 months. Over the next week I found out that it was in person when he was suppose to be going to work of a saturday to make some extra money, once a month and I also found out that he had joined a swingers website two years earlier trying to find someone to have an affair with. He had spoken to ten different women, but nothing had come of it, because the women were not able to catch up with him when he was able to. I never thought he would do this to me. I feel so betrayed.
He has told me he has been watching **** behind my back for the 10 years we have been together, even though he knows I disapprove of it. His mother introduced him to **** at the age of 10 years of age. He started to perform sexual acts on himself (to his rear end), in the work toilets over a year ago. When I told him he had a problem, he didn't understand that what he did was not normal. I got him to look up sexual addiction and he has started to realise there is a problem there.
Prior to me finding out I would have said I would leave without looking back if I was cheated on, it was not acceptable, but I find that being in this place puts me in two different minds and I don't know what to do.
On one side, he has always been so kind to me in person, we were friends and enjoyed each others company, I loved him, he has said he is eternally sorry and would take it back if he could, he said he doesn't want to loose me or the kids, he said he will do everything in his power to show me he will never do it again (he got a computer monitoring software, and GPS for his phone, off his own back), he has started seeing a sex therapist and is due to go to rehab in a week for an intensive program for a month. He cries when he hears my voice (as he is living with his parents now) and tells me he was a selfish man and doesn't deserve me, but doesn't want to live without me and despite all the pain, I still love him and miss him.
On the other side, he cheated with this other woman for 10 months, he lied to me for 10 years, he has peverted ideas on sex and doesn't understand real intimacy, he has betrayed me and my kids, I was in hospital with our son when this was happening as well so instead of enjoying this time with his wife and new son he was rushing back to be with this woman, he's addicted to **** and this sex act of his and I fear even with therapy he will do it again.
I don't know what to do. My children love their father and are both upset when he leaves here now, my daughter still wakes everynight in tears (despite the fact that we have been quite pleasant in front of her), I will struggle to keep things going for my kids on my own. I miss him everynight and though I'm angry with him, I still want to turn to him. I have hope of hopes that his therapy will change him and he will be the man I want him to be, not this monster he has been hiding. I feel that he is not a bad person deep down, that I basically know him, he has just made some very bad choices. I'm angry at his mom, as she encouraged his **** usage, told him that cheating was normal in relationships and has caused fights in our marriage because she constantly interfers. Is it this **** addiction that created this monster? Do I really know my husband? Will he overcome this problem? Will he ever do this to me again?

Why did you do this? I loved you with all my heart.
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May 9, 2012