I can't even speak full sentences because of my breathing problems! What can I do?

Depends. Depends on the cause of your breathing problems. Should see your doctor, who should examine your lungs with a stethoscope and get a chest x-ray and also pulmonary function tests to determine the cause of your breathing problem. This diagnosis will then suggest the best treatment.
Shortness of breath. When people are so short of breath that they cannot complete a full sentence, we typically consider inpatient evaluation. Both pulmonary and cardiac problems can cause shortness of breath. I strongly recommend evaluation by a physician as soon as possible.