My ex left me for someone 10
Years younger (ouch) about 3/4 months before Xmas. I was like you, hurting and to be honest wallowing in my own self pity. I could see no light at the end of the tunnel. My little one was the only thing keeping me going. I didn't even want to buy a tree that year but I forced myself to do it and put on an act to make life as normal as possible for him.
Between Xmas and New Year I got the news that my friends husband had been diagnosed with cancer and been given 3 months to live. He was in his 30's.
At that point my crying stopped and I realised how lucky I was. I was alive, I had a child, I had a loving family around me, I lived in a nice house and I was healthy.
The New Year was a new start for me. I started divorce proceedings, decorated all of the house, started to socialise again and in a few months tears had stopped and had been replaced by laughs.
I started to date again using my time when he had the little one to enjoy myself and let me tell you this, I did enjoy myself!!!!
I changed my job that I hated and now have one I love and took my son away to Spain on my own which proved to me that I didn't need him.
This was over 10 years ago and in that time I have had some great experiences, have a DP that treats me well and actually a good relationship with my ex and his wife despite what they did.
Life is too short and what happened to my friend illustrated this to me.
I'm not saying don't cry and don't grieve for what you had but I would say live for the day, be grateful for the three children you have, your health and see this as a new chapter in your life, not the end of your life.
It is amazing how many new adventures you can have in life when you are forced to do so..
Good luck and happy Xmas x