It sounds like my son. He is HG, 2E with visual processing issues. He cannoot get thoughts down on the page the way most of us do. he needed to be taught a more graphic way to organize. we also had him stand up and deliverhis ideas like a speech, or use a tape recorder and then write. The best thing that worked was a mind map or web graphic that he used to out line his thoughts then we taught him to write a sentance or two for each arm of the web....

we also use colored post it nots and he writes one idea on each note, assigns a tpoic or point to each color and he writes a note, sticks it on the table, writes a note and sticks it on the table.... then he reorganizes them in collums and then her writes. brutal but it works and he no longer has to do all of this but he did for about a year.
joAnn