Mm, my dad died just over six years ago, and you're right. Christmas sort of ends there. I suppose that it's different for people with children.
You're absolutely right with imposter syndrome. I constantly feel like a fraud because I keep finding myself in pits of creative despair which ultimately lead to me not finishing work. I don't feel like I can call myself a legit artist because I'm not publishing comics online or in print with any sort of regularity and that voice in my head is constantly telling me what I'm working on is rubbish.
I've found recently that if I work fast, I can outrun that voice in my head. By the time I hear "this is rubbish", I'm already 80% done so I feel more compelled to finish.
My goal for this year is to keep outrunning that voice.
For what it's worth, your work is always astounding and I enjoy flipping through the books I've read just to soak it all up :)