Exhausted....

I'm so emotionally exhausted.  Somedays I feel like I can't go anymore.  I feel like I'm the only one giving - but why?  He was the CS, he should be the one giving everything - but he is content with staying and having a wife and kids.  I struggle with my own emotions - somedays I just want to leave - I want to leave the pain and the hurt behind - just run away from this mess of a life he created.  I'm doing everything to get myself better, I'm in IC, I'm going out, I'm having fun with the kids, taking care of me and I know I don't need him but I want him in my life, in my kids life.   Somedays I feel like a clown - a big old smile in the outside and laughing but not happy in the inside.  I wish to be happy again,  I wish not to worry about our future, I wish for the pain to go away, I wish for better days. 
God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.