I am lucky enough to have a dedicated space to write (a studio in my garden). I have found on days when I feel I can't write or am struggling, by just sitting in there and not panicking, I start typing. That is one of the main things actually. Don't wait for 'inspiration;. Writing is hard work. Just sit and tap and edit, edit later. I heard it said recently that you need to write fast too. It helps to outrun the fear we ALL HAVE!