(TLDR question at bottom) This post will be ridiculous in nature as I am rambling mainly out of fear but I just experienced something awful that occured. I had some food yesterday evening and soon after, my throat began to slightly constrict. I don't know why but I lost my mind, thinking I was having an allergic reaction and that I soon wouldn't be able to breathe. I never had a panic attack before but I've been having them constantly since yesterday and it's debilitating. The main cause of death in anaphylaxis is lack of oxygen right? So my question is:

Is it hypothetically possible for the invention of nanotechnology embedded in a person that delivers oxygen to them when levels are low?