I had a bad case of this very recently. The holidays really sucked the life out of me around the same time I was dealt a pretty leveling blow when I realized some parts for a project I was really looking forward to working on were too small and would not work. I moped about for a bit and piddled with a few things, but my main source of inspiration came from my
Shelf of Shame. After going through some failed projects of the past I was determined to not let my Death Guard wind up sitting next to my Necromunda-era Arbites, or my 2nd ed Stormboy squad. *shudder*
It took a while to get back on track. I started out slowly with a couple
SoS Necromunda Redemptionists. It was relaxing and fun, and I never pushed it, I only painted when I felt like it instead of feeling like I *had to get this done RIGHT NOW* like I feel w/ my Death Guard sometimes. It wasn't long after that I made myself pick up an unfinished unit that I completely hated painting (7 Death Guard Terminators) and finally finished them. I felt at once an incredible feeling of relief and accomplishment. Once I got back on track the flood gates were ripped off the hinges and I got more work done in a few days than I likely would have in the weeks I was down.
It will come back. If you have to step away from it for a while, that's ok. Sometimes a break is actually a good thing for your modeling and painting once it is over.