hello, You should visit the doctor and get yourself evaluated. Get ecg done. It s never late. There are two possibilities one is heart attack and second is gastritis and reflux disease. You need to be started on medicine. Did you have any sweating, palpitations, pain going in left arm etc if yes it further suggest heart problem. Did you have any nausea, upper abdominal pain, bloating burping etc, if yes it favours gastritis as a cause. Still you should visit asap and get investigations done.