If her gums look pale, that really worries me. Pale gums can be a sign of heart disease
(which can cause lethargy, wheezing and weakness), lung problems, or she could be anemic (low red blood cell count).
If I could I would be checking her for a heart problem by listening to her heart and lungs, and feeling her pulses.
If that all seems normal, I would next check her red blood cell count to see if she is anemic. There are several things that can cause anemia, such as infections, and autoimmune disease.
I am pretty worried by what you are describing. If you can get her to a veterinarian today, that is what I would recommend.
Good that she is eating and drinking. Until you can get her to a vet, keep her hydrated and drinking. Can you take her temperature with a rectal thermometer? Normal is between 101 and 102.