These are serious symptoms and reflective of either heart or lung disease. The low oximetry numbers and blueness of your fingertips suggest that the
atrialAtrial fibrillation/flutter
Atrial myxoma
Left atrial myxoma
Right atrial myxoma septal defect (ASD) may have re-opened. ASD is an opening between the right and left sides of the upper portion of your heart allowing blood to flow from the right side of your heart to the left. But, your heart may be fine and the problem could be in your lungs. You need a thorough evaluation of both your heart and your lungs. This should be done as soon as possible.
JCI, RRT RCP