I agree with Ashtray - things get easier after a while.
My dad was crappy for all sorts of reasons, but oddly, through all of it, the things that hurt the most were the following. Being told that obviously his new wife is his highest priority. I look at my children and can't imagine how another person would be more important to me than them.
The other was putting in the divorce papers written by his solicitor and given to DM, 'There are no children of the marriage apart from one, independent child.' The independent child was DB2 who was 12. I was 16 and not yet financially independent. There are two other children.
In all the drama and upsets and fights and unrealistically high expectations of us and the 'discipline' that was over the top, it really, really stung to be vanished like that.
So it's normal to feel desperately sad. But, it does get easier, particularly when you start deciding on things on your own terms. So, no, he doesn't get to have a Christmas with you. No, he doesn't get to call whenever. These need to be your choices. They will be hard at first, but taking ownership of who sees who when will become liberating in time.