Mood swings after miscarriage

I had a miscarriage at 6 weeks last month, and I have found that I am having crazy mood swings. One minute, I am sad and crying (esp every time the dr calls to tell me the hcg isn't out of my system yet), and the next I am irrationally angry... especially at my fiancé. It gets worse at night, and even little things like him snoring make me so upset. I noticed that when I found out I was pregnant, I had been increasingly agitated with him, but now it's to a whole new level. And the poor guy has been so sweet and supportive despite my craziness. Is this normal? Do you think it's hormones? I feel like I'm losing it. :(