Do you ever have "bad weeks"?

Do you ever have "bad weeks"? I've started a new job a couple of days ago and since then I've only had bad days. My stress and my anxiety is high and I can't barely talk to my workmates, which leads me to sometimes say stupid stuff just to try to be a little participant (it's hard to explain). It's really frustrating. Maybe I need to be more relaxed? How do I do that?