Overestimated Income in 2018 and received a ACA (obamacare) Advanced Premium Tax Credit.

In 2018 I overestimated my income , received a ACA (obamacare) Advanced Premium Tax Credits, but I would have qualified for NJ Medicaid .  I adjusted my income in December 2018 and did receive a Medicaid notice.  I received both a  forms 1095-a and 1095-b, but received the full year of credits due to lag in sign up at the end of the year.   I have applied for extension of time to file.

Although I planned and estimated to have income through self-employment,  I was unable to get any work.   I have a few hundred dollars in expenses.   Is there going to be an issue  with paying back the credits ? Should I file a schedule C with these few expenses ( to show an effort to create income) or  wait for a tax year when I have income ?