I wish I could offer you advice but I myself just posted on this site for the first time today. I know what you mean, your heart and head are in a conflict. It is so complicated. Soon I would have been married 30 years. Been with H 4 years before that. Read my post. It isn't any easy no matter how old you are. I do feel badly for you since your kids are young. My sons are in their 20's and it is still hard for them. What is sadder, their girlfriends experienced the same thing with their moms. One got divorced the other came back after being away for 8 months. My H has been living on his own for 7 months but he mentally checked out on me years ago.
The only advice I can tell you is to make yourself Happy. Keep a journal on what things in life make you happy. What do you do for yourself that makes you happy - read a book, drink coffee, go for a walk, go on the computer, talk to girlfriends, etc.
Then the best advice I got was to be patient and let time take it's course. We can't control a person or a situation. Let it go.
Yes it does help being on medication. I now take it everyday. Was on every other day but with what would have been my wedding anniversary, then Thanksgiving and Christmas & New Years, it is too over whelming. I am totally alone. Have been since March 20, 2010 but really, as the therapist said, " you have been alone for years. You just had a body in the house."
H and I are friends. We will always love each other but that is where it ends. He really didn't want to reconcile. He wanted it all on his terms. One argument or emotional setback on my end and he was gone. So much for telling me he was going to stay with me forever even when he said he wanted to reconcile.
