I like to think of writing (or any creative work, really) as a large-scale process with many intermediate steps, like say, producing diamonds. You have to start by locating the raw materials, drilling them out, getting a sense of what they are, isolating them, cut them up, polish them, set them, present them, sell them.
Block can happen at any point along the process. It could be that you don't have enough raw material. It could be that you're not sure how to cut the particular stone that you have. It could be that you've got the wrong tools for the job, or that the job itself is not worth doing.
The challenge is to zoom out from the present moment and to see the bigger picture, and often to move upstream in the process. Sometimes you need to abandon the process altogether, and maybe return to it later.
The creative person's anxiety and paranoia can seem like a petty thing compared to say, somebody who has to deal with "real" problems. (I'm reminded of Anthony Bourdain saying "Cooking professionally is hard work. Writing is a privilege and a luxury. Anybody who whines about writers block should be forced to clean squid all day")
It's a fair point. That said, I think it's useful to try and understand what exactly the block is. It's fear, anxiety, attachment to outcome, a sense of incompetence and worthlessness.
Elizabeth Gilbert also has a great TED talk on dealing with that, about separating your self-esteem from your work: https://www.ted.com/talks/elizabeth_gilbert_on_genius?langua...