I Was Diagnosed With COPD/Emphysema(sp?) A Few Years Ago. Before

I was diagnosed with COPD/Emphysema(sp?) a few years ago. Before this past Thanksgiving my Dr. put me on oxygen while I slept. After Christmas, all h@#l broke loose and I'm on it 24/7. It seemed as though it was overnight and my levels would drop to 58 at times. I'm certain this has been sneaking up on me as I would be driving or in my home and felt horrible and would take myself to either a minor emergency room or the emergency room at one of the hospitals here in Wichita. The Dr.s said my sodium, magnesium and potassium levels were dangerously low and was admitted for a few days. But the feeling I was having then and now when my oxygen level is low feel the same. I'm extremely tired all the time, I get winded quickly, my ankles swell and I feel anxious several times a day. I currently take Lorazepam for anxiety though. About a month ago, I was getting ready for bed and this feeling of maybe a heart attack came over me. My stomach was upset, had strange pains (warm sensation with pain) and my arms hurt. I don't know what to think anymore as I'm only 60 and this all happened so suddenly. I'm going to a Neuphrologist for my kidneys as my last lab and urine test showed something in regards to my sodium level.