Heartbroken & confused

Hi, not sure where to start as I've never done anything like this before. I met my partner last year and we clicked instantly, within weeks we were in love and besotted with one another. We barely spent a night apart if we could help it apart from the odd occasion when work commitments didn't allow it. Since December he has more or less been living with me and we discussed taking the plunge and him giving up his flat all through January and February, we finally decided we would and he gave his notice to his landlord. 5 weeks ago we were sitting side by side on the train on our way to pick up our new car and he sent an email to his children's school teacher regarding a parents night appt and when he clicked to send it all these LinkedIn email addresses popped up. I knew he had a LinkedIn accountant as he sent me a friends request on it when he opened it on January 7th, I questioned jokingly that he had a picture of himself with our cat as his profile picture and not one of us together and he replied I hope you don't think I'm on it for anything sinister, it's purely work reasons and I will shut it down immediately if you want me to. Me being the trusting person I am told him not to be silly and I was happy for him to be on it. Boy do I regret that now! After seeing the LinkedIn email addresses I became suspicious, so the following night while he was asleep I got up and checked his phone, something I had never done before. He had given me the passcode within days of us meeting so I never thought for one minute he had anything to hide. What a shock I was in for!

There was numerous messages to women asking for their phone numbers and telling them he found them attractive, I was completely and utterly devastated! I was due at work at 7am the following morning and I stayed up all night crying and shaking, he woke up at 5.30am and asked me what was wrong. I didn't tell him I had looked through his phone but I told him I had a bad feeling he was up to no good and wanted to look through it. He gave me his phone instantly and once again I looked through the messages this time in front of him, the whole time he kept saying it didn't mean anything it was just chat. I was in such a state and not thinking straight I instantly made him close down the account as I had to leave for work but in hindsight I wish I had taken his phone to work with me so that I had more time to look through his phone numbers etc. He had offered me to take his phone but I refused. Later once I got back home I went through all his phone bills for the previous year since we had met, there was absolutely nothing on them prior to January 9th and then BOOM! Right after he had joined LinkedIn. There were messages upon messages to several different numbers, a few phone call and picture messages. Most of these were sent when he was working during the day and when I was out working nightshift.

Two numbers stuck out in particular, one of them I traced on Facebook and sent her a message telling her what he has been up to, she called him a few choice names and said that yeah he had been messaging her but that's as far as it had or would have went. The second number I called with him sitting beside me, it was a woman who said she used to work with him and she had bumped in to him at the train station the first week in January and he had looked her up on LinkedIn, they text constantly for 5 days with 1 phone call and picture messages. She told me that he had sent her an explicit message and that she blocked him which I believe was the case as the messages to her stopped on January 13th. To point out since I met my partner he has been the kindest most loving romantic man I have ever met, constantly sending me messages to say how much he loved me and has never been happier and he couldn't live without me. He instantly changed his phone number so these women couldn't contact him and he phoned each of them from my phone explaining what he had done and how much he had hurt me and loved me and that he would never contact them again.

He phoned his mum and told her what he had done to me because he knew how much of a hard time he would get from her and he wanted to show me how sorry he was and that he didn't think he should just get away with it. He offered to give me his phone, said he could live without it as long as he still had me but I refused so he bought a spyware app and installed it on my phone and his so now I can see every single thing that goes on in his phone and it does work even though I am racked with guilt every time I look at it but I need these reassurances at the moment. He calls or texts me to let me know where he is going every time he leaves his office even though he knows I can see it on my app. He swears he loves me more than anything in the world and do anything to try and repair the damage he has done. He cries all the time saying it is killing him knowing what he has done to me, he says he doesn't know what happened, he was genuinely the happiest guy in the world with me but he got caught up in it all and it escalated, he started to get and ego boost from it all, he says he is utterly disgusted in himself and that he will never ever do anything like this again and he will go above and beyond to prove it to me. I don't know what to do, I am hopelessly in love with the man that I thought he was and I can't imagine my life without him but I can't stop thinking about it all and its destroying me inside. He offered to go to a hotel to give me time to think and he would leave his phone with me but pathetic as it sounds I hate the thought of being apart from him. Whenever we go anywhere he always put his phone straight in to my handbag, I think it's just his way of trying to prove to me he has nothing to hide. I'm hoping someone will reply that has been through something similar and can tell me if it's possible that a man can change?

Do you think seeing what this has done to me will be enough to stop him ever doing it again or is he saying whatever he thinks I want to hear? He has handed the keys back for his flat now so he would need to start again and find somewhere to live, I love his mum and his children and my son and family absolutely adore him also so it's not as cut and dry as just walking away. I really really want to believe that this was some midlife crisis and he realises what he could lose because of it, I also wonder if it's a psychological thing as his ex partner was possessive and jealous, according to his mum and his inlaws he didn't have the life of a dog with her even though she was the one that cheated on him several times and even got pregnant to another man while they were still together. Is he emotionally scarred from all of that and then once he got with me and there were no trust issues and he had all this freedom he got carried away? Please please please give me your thoughts on all of this. I have absolutely nobody to talk to it about except him as I am completely humiliated about it all and don't want to tell any of my family or friends. I'll just add that he wanted to tell my family what he had done but I wouldn't let him. Thanks so much for taking the time to listen me