PoeWar has a bit of a how-to (mostly it’s a how-to not panic!).

Don’t Expect Perfection

Accept that what you write on the first try only needs to be good enough for a first draft. Try to avoid going backwards and rewriting what you have already created. Instead, if you know something needs to be changed, go back to that point and make a note in the text, then move on.

Stay in Motion

If you get stuck, find a way to get unstuck quickly. If you know that a scene needs to happen, but you aren’t ready to write it yet, make a note in the story describing the basic events, then jump to the part that you are ready to write and get going. If you need to choose between two different directions for the plot, choose one of them and don’t look back. Your focus should always be on forward momentum.

Read the whole thing – it will make you feel better. Say, did you invest in that coffee machine yet?