I can't calm down! Can someone please help me?

I am about to become a first time mother. I've been married for three years. The pregnancy was unplanned. My husband and family have been supportive but now that this has become a reality, I'm beyond afraid. Things were going great before the pregnancy. I liked my job, I liked my home, I had a nice schedule. Now, I am quitting my job to stay home and raise my son ( My salary wont cover the cost of daycare) and my life is completely changing. I have no idea how to be a mom or a house wife. I don't know if it can be done financially. I feel so alone and terribly sad. Can someone help me?