Don’t worry about that; it’s definitely not just a you thing. There have been plenty of days I decide I’ll sit down to write, and then just stare at a blank word processor, nervously poking at it with a stick.
In my experience, inspiration likes to arrive unannounced. There have been several times when, after nights of writing a few sentences at a time, one night I sit down and just suddenly write over 1,000 words. I think there’s a good chance it will just suddenly happen like that for you. 😄