It was a month ago that I was sitting in a restaurant and suddenly I felt I'm not getting enough air. I had trouble breathing and wanted to get outside so I can breathe some air.i also had light headedness and feeling of about to faint. There were numerous episodes after this similar. I visited multiple doctors who took my blood test, chest x-ray, ECG ,echo and tmt done which all came normal. I also started to have trouble walking on road where I would get tired, racing heart rate and some chest discomfort and palpitations even at rest or sleeping. I also had an episode where I was carrying garbage and felt my heart racing and was going to explode. I took some rest and finally got back home. I went to doctor and Finally I got my vitamin levels checked where vitamin d Wass 5.12 & vitamin b12 was 214. I'm now taking supplements. Anyone had similar issue? How long will it take to recover.