I cannot do deep breathing, or diaphragm breathing. When I do I instantly get faint, my vision gets staticky and I get very spacey. I also feel like this when yawning. Has anyone else experienced this?? Last week in my physical therapy session they asked me to begin belly breathing and I immediately begin feeling unwell, I then fainted and went into convulsions. I am convinced it was from the breathing not tachycardia. Any thoughts??