OtherMummy, big hugs for your hurt feelings. I'm sorry you are feeling violated and sad and angry and probably a hundred other emotions right now. December is a difficult month to get through but try to relax, it's supposed to be a month filled with family and love and celebration.
I was a single Mom for a lot of years and did everything possible to give my children great Christmases and memories so I understand the stress you're under but I realized as I got older that the amount or size of the presents isn't what my children remember. They are all adults now and remember the traditions and closeness and fun that we had, not the actual presents. I don't know how I did it, but I stressed myself out terribly every Christmas. That was wrong!
Sending you more LUCK! Fill that space!