Based on the symptoms you described—feeling like you have a lump in your throat, frequently taking antacids for heartburn, and experiencing chest pains—the illness that makes the most sense to evaluate would be gastroesophageal reflux disease (GERD). GERD is characterized by chronic acid reflux, which can cause heartburn, a sensation of a lump in the throat (often referred to as globus sensation), and sometimes chest pain.
While the other conditions you mentioned (osteoporosis, hypothyroidism, and type II diabetes) can have various symptoms, they are less directly related to the symptoms of heartburn and throat discomfort. Therefore, it would be advisable to evaluate for GERD.