I have been struggling to write anything lately.
This is due to two factors.
First, I simply lack the time to do so. The first half of my current manuscript was hammered out in a relatively short time while I was unemployed and looking for work. I had loads of spare time on my hands, and could type away for hours each day. This freedom has been seriously hampered by the two jobs I currently have. I work 8 hours during the day, and again 2 or 3 hours at night. Between getting to and from work, eating, showering, doing the laundry and getting the grocery shopping done, I barely have time to get into bed on time.