Along the lines of what John August says about writers' block, some useful perspective from Working Writers:
Beginning a new story is difficult. The first three chapters are a notorious pain in the rear and many writers – professional or not – wrestle with these beasts more than any other portion of the book. This is completely natural and the only way through it is to write and keep on writing, even if you don’t like what you’re typing. There’s nothing you can mess up in the first draft that isn’t fixable in revisions and there will be revisions a plenty!
and also
Writing is mentally exhausting, take breaks. When my brain feels like goo and I fear it’ll run out my ears, I get away from my desk and do something to refresh. Walk in the garden, do the dishes or laundry. Whatever you decide to do make sure it’s relaxing, relatively brainless and not distracting like, say, chatting on the phone.
Check out the rest here.