Symptoms sound a heap like Delta-Covid. Ain't no picnic when you feel bad, your saturated O2 tanks, and when you breathe it doesn't do any good.
There is an inexpensive O2 saturation monitor that fits over the end of a finger that can help steer you to health or hospital. Supplemental O2 (bottled oxygen or oxygen accumulator), if you have or can get it, might give you the relief you need, and keep you out of the hospital.
Hope you are better soon - and without a trip to the hospital.