I agree with @ucbalumnus .
Depending on your income level, as a single parent and an income level under a certain level, you might only be required to file FAFSA at some schools.
At schools that do require non-custodial parent information, do yourself a favor and schedule an appointment with a FA director. They are ALL willing to help work with you and have ALL seen this before, so they can tell you the best course of action. Most are helpful to families even before applying, but definitely before commitment