possible h pylori PLEASE HELP!!

Hi, I’m a 19 year old female and have never had any serious health issues so my health anxiety is through the roof. I started going to the doctors at the beginning of summer because I felt my health declining. My doctor was so sure it was gallbladder related, even though a majority of my pain was on the left side of the stomach. I have done all testing relating to gallbladder and it shows it’s healthy. I got a second opinion from another doctor and they suspect I have a nasty infection. I developed awful heartburn and acid reflux (I burp constantly after drinking water and eating). I also have extreme fatigue, nausea, dull/crampy stomach pain, urgent diarrhea (sometimes odd colored, like yellow. Sorry tmi), heightened anxiety, unexpected weight loss, lightheadedness, and excessive sometimes clear or yellow mucus when passing stool. I began taking fiber and it’s helped slightly. I am now experiencing burning on the left side of my stomach where my pancreas is and I’m worried an infection could be effecting other organs. I suspect c diff as well but not sure. Please tell me if you experienced this, I have to go back to school soon and I don’t think I can deal with this away from home.