I'm just a hobbyist, so take it for what it's worth.
I go through a lot of phases where I struggle with being able to shoot anything. I just let the camera sit for a while, then make myself go shoot something - even if it is just playing around with tabletop stuff. Another thing I have found helpful, is to participate in memes and challenges at a photo forum. Forces me to get out and shoot, to shoot using only a selected focal length, or to shoot my interpretation of a subject chosen by someone else, etc...
With regards to mirror-less. Changing gear because you are bored or currently lacking inspiration/ a desire to shoot, may cost more than you think. If you become re-invigorated, you may wish you had kept the gear you sold and end up re-purchasing when you find the mirror-less isn't meeting your needs. I'd suggest making sure you want to go mirror-less before making the jump.
As trg42 mentions, some of the mirror-less gear isn't inexpensive and can actually exceed the costs of some of the APC-C based DSLR gear. I'm currently shifting most of my gear to the Fuji X system, with a mix of Fuji glass and adapted M-mount glass. It's definitely not inexpensive, if you are looking for performance approaching what you get with most DSLR systems. I'm not doing the switch due to anything other than increasing
bio-mechanical issues that are making the use of the larger and heavier
gear much more painful.
I'll end up with just my D700 with a 24-85 and 80-400 in the full-size gear column, for when I want the responsiveness and AF performance. The Fuji kit will be used for everything else, and the M-mount glass brings more "fun" back into the game for me as I prefer manual focus and I find the X-T1 to be so much more easy to use mf glass with than the D700. If Fuji continues with their improvements in AF performance and starts releasing longer glass, the rest of my DSLR gear might be gone in 3-4 years. It would be less expensive to just upgrade my D700 than to switch, but the new system is more compact and lighter with excellent IQ and adequate performance.