Affair is over - how do I let go?

I am not proud of the affair I had, but its been the best 2 years of my life, especially for 3 months straight recently where my mistress and I were able to practically live together.
I guess I had hopes we would ALWAYS be together part-time. We live on opposite sides of the country, but somehow made it work. I love Carmen so much - but the fact remains that she is single, and I am married.
Due to a change in jobs, I no longer have the freedom I had before to travel.
I think when I left her at the end of March, we both somehow knew it might be over.
I have considered leaving my wife....but unfortunately it's not just my wife. It's my wife, kids, home, family, etc.
I can honestly say though, that I love Carmen more than I have ever loved anyone in my life. We matched on so many levels.

Now the problem....
Carmen always had a "guy friend" who she would hang out with every now and then. If they went to a movie, they each would pay their own way...it was strictly platonic, and I believe that.
2 weeks after I left, she went to the Larry's house for dinner. She was still distraught about me leaving, she cried a lot, he comforted her, and they ended up having sex.
I was so hurt. I am still sick to my stomach thinking about it.
But I have no right to be hurt, right?
I just thought that was WAY too soon to move on from us after all that we shared. 2 years together, and the past 3 months completely together, and she did that after 2 weeks of me being gone.
She has the right to live her own life, I understand that. She had to deal with me being married and sleeping with another woman (my wife) every night I was home. As cliché' as it sounds, my wife and I are more like roommates, and have not been intimate in years. Carmen knows this - but here she is sleeping with another guy so soon.

She and this guy are "dating" more and more over the past few weeks. And it kills me thinking about it. I knew eventually she would have to get on with her life, but this was just too soon for me.
Maybe I was secretly hoping there was a way we could always be together, but now with her and Larry together, its not going to happen.
I am sad every day thinking about it all.

How do I "let go" of my feelings for her? I love her so much, but she deserves someone who CAN be with her full time.

How do I stop thinking about her, and her and her boyfriend together?? I lay awake at night and wonder about them and what they might be doing right then.
I dont sleep.
I am jealous of Larry....he is with the woman I love so very much.

She has my heart, but how do I move on? We text and call each other several times a day still.....we still say "I love you" and all of that.
But I know I have to cut the cord.
Help me figure out a way to do that, please??

Sorry for the long post.