Something I've been doing the past few weeks, probably to the dismay of some people, is randomly giving myself odd writing challenges. Things that pull me out of my comfort zone, to try something I wouldn't normally write. Rhyming, bad poetry, short stories on quirky topics, and such. Bad poetry is especially fun to write.
If you're not writing anything at all, I really recommend at least trying something small like that, unrelated to your projects, and seeing if you can get a little bit of anything down. 1 page of a standalone short story is better than 0 pages of nothing.
A full storygame is a big commitment, and it can definitely get tricky trying to organize thoughts enough to get anything down on paper. The hardest part, for me at least, is getting started with the first 20-30 pages. Once I finally get a rhythm going and better feel out the player character's interaction with the world I'm trying to build, then the writing starts flowing better.