You're still clearly way too invested in him and the marriage, and from the sounds of it, he no longer is. I hate to say it because it sounds so trite, but when a man tells you something you don't want to hear - that he's no longer attracted to you or in love with you, you need to believe him.
You can't make him feel what you want him to feel. You can't make him think what you want him to think. And you can't make him behave the way you want him to behave.
That's the unfortunate truth you're facing.
And that is why an in-house separation would be far too painful for you. Just the way you're feeling right now - aching for him to love you and pay attention to you and touch you while he's being indifferent 90% of the time and saying he's no longer interested in staying together is going to slowly crush you.
Lastly, this is now the 2nd time he's cheated - that you know about. Why are you so eager to forgive him yet again? The utter pain and devastation he caused you the first time he did this - and watched you suffer - wasn't enough for him the first time?
You really need to ask yourself why you'd forgive someone who can keep doing this to you.
I understand the need for his touch, his love, his support - but now is not the time. He is the source of your pain, he cannot be your comfort.
When infidelity strikes, it tears at our own sense of self - our self identity. You want, need to feel whole, you yearn for what you once had - it is only natural to desperately want the WS back.
However, before that, it is better to heal - to build up a new self-identity that is a bit further from the WS. You need to rebuild your self-esteem and your identity.
The 180 rules are a set of guidelines on how to behave during this terrible time. - read them, they help - http://www.survivinginfidelity.com/faq_bs.asp#FAQ11
Read the many threads on the 180.
I'm so sorry for you. Be strong - or at least pretend to be strong, even if you feel totally broken.
It will get better
Loving someone unconditionally does not come with butterflies in your stomach and 100 of text messages everyday. It is a mature love, it is an AGAPE love. It is a "will take a bullet for you love"
The puppy love, my WS and your WS want to feel is the stuff kids feel in highschool...
It is an addicting feeling and they love it and seek it out. My WW will not go NC as she is addicted to feeling the puppy love feelings. But what are feelings anyway...well they are chemicals. So the puppy love is nothing less than a chemical addiction formed in someone who is emotionally underdeveloped.
It is hard to not take it personanally when the WS says, I am not i love with you but in love with the AP, but the AP is fooled too, like our WS, they are chemically addicted. I no longer feel sorry for myself, but feel sorry for her.
You should feel sorry for him. He is the loser. Cheaters never win and winners never cheat, its not cliche, its true.
You are the winner. Good luck, stay strong, you will get through this and if you keep your mind sharp, you will come out of it better stronger and more capable of loving someone (him or someone else) better than before as you are (We are) going throught an equipping period in our life.. Built up, not torn down.
Agape (love) to you!