Is it normal for me to be short with my mother because of a family tragedy?

My father died earlier this year from Non-Hodgkins Lymphoma and it's been a really difficult year for me. I was able to make the dean's list at my college the semester he died (two weeks before finals), so I was pretty proud of myself.

My mother says that since then, though, I've become increasingly short-tempered and irritable in general with her. She talks about moving out of this house (I grew up here, she was moved around as a kid like an army brat) because she hates it and she thinks it's badly designed.

When she talks about basically the only home I've ever known that way I just get really angry because of all the memories I have here and because the thought of some strange person living in my home or room creeps me out to no end.

is it normal for my mood to be this way months after my father's death or am I just being selfish like my mother thinks?