There's no such thing as talker's block.
Yet we bang our heads against the wall all the time trying to figure out what to say in our writing.
The problem is one of filtering. You have a subconscious belief that what is on your mind is not good enough to put on paper.
So here's an easy brain tweak to get you more productive as a writer:
Realize you don't have to publish it.
No one else ever needs to see it.
Step one is to get whatever is on your mind out of your head.
If you're already thinking about what other people are going to think of it, you're way ahead of yourself. Get that idea out of your head and just start writing.
You don't have to publish it.
I started writing something completely different for this post. I was writing it, all along thinking it was shit. Then I realized, hey, I'm totally happy I got this out of my head. And I don't have to publish it. So I erased it all and wrote this instead.