Have hp pylori blood tests came back positive. my stomache was swollen took antibiotics then it went down. after meds finished it's back. my back feels like knives are in it and my stomache pain is so severe?

Many possibilities: Upper abdominal pain can be from acid pains such as reflux heartburn, stomach ulcer, or just gastritis with no ulcer. Sometimes there is an ulcer in the first part of the intestine. An infection with H. pylori bacteria can lead to ulcer pains. Pain may need evaluation by the doctor. Constipation, pancreatitis, gallstones, muscle strains, tumors, spinal nerve issues, etc..., can also cause pain.