I'm sorry your Christmas turned out the way it did. Last year at Christmas it was awful. Not as badly as yours, but I know how it feels to have a day that is supposed to be special go to sh*t.
As for telling you how to let go, I wish I had the magic answer to that question. It's not easy and it's a process, and even after 11 months I don't know if I've completely let go. I guess you start by thinking of yourself more, doing things that benefit YOU and make you happy. I'll suggest the book "Codependent no more" because it truly was a wake up for me.
I know you want to hurry and leave so you don't beg and plead with your H, but I still would caution you on jumping the gun. Don't react out of emotion. Just give it some thought.
"Everyone you meet has baggage. Find someone who loves you enough to help you unpack." ¤Formerly DelinquentGurl¤