How to manage H.pylori infection?

Hi doctor,

I am an 18 year old male. I have been experiencing a wide range of symptoms for nearly a year. It all started in the last summer. I started to experience constant vomiting after eating, bloating and weight loss. Then, I was diagnosed with a Dientamoeba fragilis infection and given a course of antibiotics. I thought I would get better after this, but that was not the case. I was treated for the bacteria and I still have symptoms like occasional vomiting, a lot of weight loss (15-20 pounds), bloating and abdominal swelling. The doctor did a bunch of blood tests and said he did not see anything wrong. The vomiting stopped, but I still experience the symptoms and not gaining any weight. So, my doctor referred me to a gastroenterologist. I told him about my symptoms, which are as follows. GERD, weight loss, occasional abdominal pain, abdominal swelling and bloating, malnutrition, alternating diarrhea and constipation, and heart issues like racing heart and heart palpitations. My sister has celiac disease. My gastroenterologist has done an endoscopy and said he does not think that I have celiac and he said Helicobacter pylori might be a possibility. I am really worried because I have got a lot of blood tests and everything came out fine, except Vitamin B12 and D deficiency. So, I just want to know if you think that I could have Helicobacter pylori. I am really anxious. Please explain as soon as possible and share any other possible illnesses that I could have based on my symptoms. Thank you.