Apparently it's all my fault, he's only moody because I've been (in his words) "Ultra Dramatical" this week because I'm on my period.
We all choose our behaviour... you dont make him behave the way that he is, he is choosing to behave that way.
People interact in all types of ways, some days something can be said and we will laugh it off, other days we wont... its not the persons fault that said it, its us choosing to react.
You may have low tolerance and being 'ultra dramatical', but how he choses to respond is his problem/fault... kwim???

Hang in there hun, tread lightly this week and hopefully he will get what ever is stuck up his bum out soon !!!!! I know its not right that you are having to be careful not to anger him, but its always give and take.... just make sure you are not doing all the givng all the time.
His adjustment to work will take a while, try and be supportive and thank him for his efforts, you have no idea how those words 'thankyou' are recieved...

take care