I think it was inevitable that your first holiday since separating was going to be challenging - whether you went to a place with memories or without. The important thing is, you gave it your best shot. Yes, it was tricky and understandably emotional it I bet your DC had a lovely time. Next time, it will be different.
You are still so early on in this journey and it’s only natural there will be downs, sometimes big ones, as well us ups. It’s ok to cry, to mourn, to wonder how it all went wrong …. I encourage you to be kinder to yourself and give yourself permission to let those feelings out.
I hope you can enjoy the time now while the DC are with Mattress Man. Fill it with work, friends, trashy telly, whatever you feel you need.
You are doing so well… you absolutely can do this!