What Causes Low Hemoglobin Levels While Having Esophageal Varices?

Sir, i have the disease of Esophageal varices. i did the banding treatment and now i am better than i was earlier. But from the moment when i was diagnosed (4 months ago) my hemoglobin level is between 6 to 7. I took iron supplements for 3 months, still the HB level is in the same position. Doctor refered to take Iron through IV. And i did the IV day before yesterday, but last midnight i went to the toilet after came out i drunk a cup of water, at that moment i had a tightness in my chest and a breathlessness. after a few minutes i slept. Now from today morning i am suffering from a body pain , like how we feel after a severe fever. Sir, is this a serious issue? what should i do now? please direct me sir, thank you.