Gonna throw my two cents on the pile. I've experienced this myself. It always a little different for me, though. I'm an amateur, self taught, slightly above hobbyist woodworker. My problem is how the shop explodes after a big project. Tools, sawdust, scraps, etc. Then, throw in being gone out of the country for several months for work (multiple times), come back, and yep....shop is still a disaster.
I've done the same exact thing. I've walked into the shop, seen the disorganized, sawdust-covered mess, said nope, and went to find the couch, feeling completely unmotivated again.
Here's what has worked for me. Like many others have already said, find something small. Find a part of your shop that can be more organized or improved. Think of a small gift for someone. Get you some caffeine going, turn your phone ringer off, tell the significant other and/or kids you'll be in the shop for a bit, and then crank up some music. Open up the doors (love me some fall weather), and take it a step at a time.
As for inspiration, check out Pintrest. There are some very creative and unique projects out there that have caught my eye plenty of times.
Hope this helps. Good luck!