Writer's block isn't as much of a problem for me (yet) as finding the time to write. I am an artist and an author, both full-time, and I have to clear time away from my freelance art commissions to make progress on my book.
Most recently, I had the opportunity to take a "writer's sabbatical" for a week. It was a week away from the world, no connectivity, no phone service. I accomplished a lot while I was there, but even with all that solitude, only managed 170 or so formatted pages. Writing ain't easy; it takes time and it can be exhausting if you encounter a day you have to force it. Those days come. But I've found that if I can fight through them, and write (especially if I have the availability to do so), eventually the muscles relax a bit and the mind opens to the next word, sentence, chapter. It's a gradual thing.