First week and I have got nothing done at work at all

Started on Monday. Everything is fine physically, no complaints, and I like it.

The problem is that I have thought about basically nothing else for five days. I sit down to work and within about forty seconds I am aware of it again, and then I am not working. I got through maybe two hours of useful output all week.

I assume this settles. I would like to know roughly when, because I have a big thing due at the end of the month and right now I would not bet on it.