I am experiencing heartburn (gerd) (worsened by: eating shortly before bed, eating certain foods, lying flat) . constipated. burping. feeling weak?

GERD.: The symptoms you have described could be consistent with gastroesophageal reflux disease. Given your age, it would be fine to trial a one month course of an over-the-counter medication like Protonix or Prevacid. Should this medication not work, or should your symptoms worsen during the month trial, then an evaluation with a gastroenterologist would be wise.