Thanks, endorphins!

Six years ago, my husband had an affair with someone I thought was my good friend.  Our families' lives were entwined to the point where I think I may have been babysitting this woman's child at least once while she was fooling around with my husband.  When I made the decision to stay with my husband, the one thing that kept me going was exercise.  I'd hit the gym on my lunch hour, bust out 30 minutes hard on the treadmill or elliptical, and come back to work clear-headed.  On days I didn't feel like going to the gym, I went to the gym.  I had a 6 year old who needed me to not be a weeping pile of mush when he got home from school every afternoon.  Some days, I had the thought in the back of my mind that the only thing keeping me from driving my car off the bridge was those endorphins. 
Fast forward to today and, surprise, my husband has been having an emotional affair with someone he met at my high school reunion this summer.  He plans to visit her next month.  I found out about this when I found the flight confirmation email in his pocket.  This was the week before Christmas.  I'll spare you the drama (for now) but this explains his sudden and complete withdrawal from our life together (emotionally) and his unwillingness to work on our marriage. 
So, despite the fact that I thought we had a great marriage and a wonderful friendship -- though admittedly we needed to work on making more time for one another -- we will be separating in March and divorcing at some point in the future.  Right now, he's so over the moon for this other woman that it's hard to get him to sit down and think rationally about what is best for us and our children.  He seems to be fine living in our family room, eating the dinners I make every night, and spending time with our kids.  He just disappears for hours after we've all gone to bed so he can call this other woman.  It's really a great set-up for him, but obviously not so much for me.
On the whole, I am okay with our marriage ending.  It's not how I wished things had turned out for us, and I am sad for our kids (ages 12 and almost 3).  The financial hit will suck for everyone.  But, really, I know I am worth more than this garbage.  I always said he was my best friend, but a best friend wouldn't do this.  My biggest concern and strongest inspiration is my kids.  I know that my husband acts the way he does because of attachment issues and abuse from his childhood.  It's sad.  I don't blame him for having issues.  But I can't allow my son to see this and think this is how you treat a woman and build a life.  And I can't let my daughter think that it is okay to put up with this lack of respect, or that she needs a man to complete her. 
Do I regret giving him another chance after his affair?  No.  I can't.  We had my daughter in the midst of that reconciliation.  We had a lot of great moments in those six years.  I wish I'd taken more steps to protect myself, emotionally and financially, in that time.  But I can't regret it. 
I've started going to the gym at lunchtime again, and it is helping immediately.  (As is the 10 pounds I dropped almost overnight in the midst of all this.)  I've been a little down all day, thinking about the New Year and how sad it is to go into the start of a new life with such a huge sadness on your heart.  Do I toast the heartache and misery that is ahead as we rip our family appart and watch our kids cry?  Can I make it through the day tomorrow without sobbing non-stop? I don't know.  But I will take my kids to the park tomorrow and we will run until we can't stand up.  We'll eat ice cream and watch the ducks and be silly.  We'll hug and laugh and dance. 
As I was getting into the shower after my workout today, I had a flash that said, "He did the best he could, but you are worth more than that."  Amen.