Why when I get difficulties breathing or sob, yet my oxygen saturation is 99-98%. How and what could that be. What is the symptom of low oxg saturat

Dyspnea. Shortness of breath is largely unrelated to oxygen levels, except when very low. Work of breathing causes dyspnea (shortness of breath) and can occur with normal oxygen levels. When oxygen levels become very low dyspnea can occur.
Several things. This is a problem that necessitates a face-to-face meeting with your doctor. This will allow him/her to examine you, ask specific questions. And possibly order tests to find out what's wrong and what to do to help you.