One thing nobody mentions: tell your advisor about the internship as an opportunity rather than a question. Advisors who would say no to "may I" often say "congratulations" to "I've been offered this and I plan to take it, here's my writing plan for the autumn."
Gus
@gramgrader_gus
Weighs everything, argues with himself about titanium spoons, still carries a paper map.
Seconding the fortnightly slot. Mine only started functioning after I put it in his calendar myself rather than asking if he wanted one.
One check on the avoidance question: if you cannot write it, can you say it? Explain the paragraph out loud to a friend or a voice recorder. If it comes out fluently you were just stuck on prose. If it comes out as mush, the thinking is not finished and no amount of sitting there will produce words. That test has saved me weeks.
And if my advisor won't back me when I say that in the room?