WA, I’m so sorry. You didn’t lose just one person – you lost three.
All you can do now is write the letter of all letters. Get your pen (or computer) out and write down everything you feel and everything you hope for in terms of your relationship. Then send the letter and hope that she reconsiders — or explains her decision so that you can make peace with it. Make sure you tell her that if she decides she wants you out of your life, you’ll respect her choice. You just want to know what’s what.
You’re right — you can’t fix this on your own, and you can’t force reconciliation. You’ve learned that she’s not the type to work on a relationship, at least not with you. She has shut you out without much sensitivity, based on your account. Of course, I do have to wonder what you haven’t told us. Her reasons for leaving may be valid. Regardless, it seems as though you need some closure and an explanation.
She has shown you that she defines her family as herself and her children. After two-and-a-half years, you’re still not a part of her pack.
Break-ups that involve children are a special kind of terrible. Often, when people break-up, they lose their partner’s friends. With kids, it’s many times worse. You have to cope with the loss while worrying that the children might not understand your sudden absence.
Write the letter. See what happens. Rent some movies. Hang out with your daughter, who is your family, no matter what.
This woman will either rise to the occasion or she won’t. In the meantime, sending a letter can’t hurt, and it might be good therapy for you.
Readers? I wish we knew more about their relationship problems, but is this letter writer entitled to see this woman’s children after a non-marital break-up? Do you think this break-up is temporary? What can he do to cope with the loss? Share here.

– Meredith