Ravenclaw,
I'm not a doctor and surely don't want to offer 'real' medical advise but I think the following is true:

The body feels the urge to take a breath because it needs to exhale the CO2 that has built up in your body since the last breath. That feeling to take a deep breath is from too much CO2 in your blood rather than not enough O2.

I don't know how this might help you, but it might be something you could speak to your doctor about.

I hope you feel better asap. You deserve that, we all do.