I Had Gastric Bypass A Couple Of Years Ago, I

I had gastric bypass a couple of years ago, I was given potassium and also my hemoglobin dropped to 6. I had 2 infusions and statred protein shakes got it back up to 13. Well I am now feeling achy all over and my neck has started hurting and yesterday I noticed tat my chest on the left upper closer to the sternum is sore to touch. I went to get blood work but am concerned because it hasn't let up. I also have soft tissue rheumatism.