When words don't come out, the writing becomes paralyzing, this is an usual feeling on people who is addicted to write but lacks on the unexpected inspirational moments which are deliciously unique, because they never repeats.
I recommend to those who fails into this situation to look for some advisor in research matters, they can help you to understand different models of writing that can fulfil your necessities of communication in a well structured and happy flow without the need of being impressive, but being clear and transmissive.
Don't be afraid, your feelings will not be silenced by the structures, that happens just with the language; you will always remain yourself and every letter that comes out of your fingers movement, represents your will.
Have a happy write!