As writers, we develop our stories by wondering “what if…”  As individuals, we must be careful about wondering the wrong “what if…” scenarios.  What if my book gets panned by Entertainment Weekly?  What if I don’t make enough money to quit my day job?  What if I only sell three copies and those three came from family?  Running through the worst possible outcomes will drive you to drink and never finish that book.  Self-doubt is a disease.  Don’t fall prey to it.  Demolish it and write the damn book.