Sorry to hear about the writer's block. Aside from poetry, you write really well when you post here. There are lots of careers that depend on good written communication. I am an analyst, mainly working with data and statistics, but most of what makes me a good analyst is being able to write about my findings. So instead of writing yourself off, try writing your way into a career instead. Look out for any community or volunteer opportunities to use your wider writing skills, maybe doing something of that nature would shift the writer's block.

BTW, I sometimes get terrible writer's block at work, it is such a horrible feeling having a head full of words, a blank page and a gaping chasm between them. Caffeine and carbohydrates, my main vices, don't seem to help much either.