Will the EPC light indicate bad gas? Chugging along trying to get rid of the gas

What is your question?

I filled up with a little more than 1/8 of a tank. Reegular gas at a cheap gas station. Drove a bit over20 miles and it started chugging and coughing and choking, hesitating at lights etc. I was told to put in Seafoam and fill it back up with Premium gas. I am trying to run all the gas out. Will this hurt my car? I am now down to right over 1/4 of a tank. What do I do next?