How do I move on?

I don't know how to do this whole separation thing. I think it's getting easier and then something happens and throws me back to the beginning again. Like I said, he went to Denver again yesterday. Supposed to be back this afternoon. I hate looking forward to him coming back. I shouldn't care anymore, but I do. I know that he has the best of both worlds right now and I need to change that. He has to realize what he's doing to me. I still love him and would probably take him back..stupid as that sounds. Then I think about not being able to trust him again and all and know that I CAN'T take him back. Besides he would never give her up, he would always want to be at least friends with her. I couldn't deal with that at all. Right now, I can ignore it some and put it in the back of my mind, but when she moves up here...damn it's going to be soooo hard to see them together all the time!! Having my kids around her and her kids....I know I have to deal with it...but HOW??
I try not to think about things when he is up there with her. It's just too hard knowing that he wants to be with her and not me. That he loves her and not me. He will text me when he's on his way home. He will let me know when he gets here. The boys want to see him, so he will come get them. I will have a hard time not asking how it went, what was said, what they did, etc. It's like I need to hear it. Torture myself more? I have no idea. But I will try to refrain from asking. I just don't know how to do this.