Medical disability

 Must I file taxes while unemployed? I am on medical disability with minimal snap food benefits which have been drastically reduced as a result of the disability. My health insurance was also vastly affected. Medicaid with Medicare now and my own health insurance? I now have to pay for an advantage plan is that right? And pay copays and rx costs. I am unemployed with a daughter who is a dependent and receives non court ordered minimal child support. Must I file taxes and what are possible credits available for my situation?