Wow, you got some nice words and wise words from MCS. I too had this feeling that detaching meant to give up. Well, it's not. Detaching is creating a life for yourself, having your own identity and individuality. It's breaking the physical and emotional dependency that we create once we get married.
So, once you understand that you can detach and still hope for your M to work, then you will feel better.
There is this path you create to have some fun, start new hobbies, meet new people, etc. But, in the same time you can think it's possible to reconcile.
Once it happen, you don't need to give up, but you will give yourself opportunities to live you life in full. As you do it, you won't feel so depressed, anxious and unhappy. You will start to smile more, feel more confident and the more you do, the better you feel.
Now, it doesn't mean you will just feel good like la la land, life is hard by itself, the pain of grieving the loss of your W will come and go. Every day it gets a little better.
About the XMas text, I think you did good. After years with someone it's polite to wish them a good time. She has her reasons do not answer.
Hey man, do you guys have some friends in common? There are any places you both used to go together? Did you text her asking if the kids could spend some time together, even if it is for a few hours just to catch up? These kids where growing together as a family and now it is all gone, maybe your W will think twice about it.
And by the way, the psychic is someone tempting, but I do not believe in these things, if it does not happen the way they said, then they are not held accountable.
Good luck, detach as much as you can because you will need your individuality even if you reconcile.
