Reasons why so tired and difficulty breathing.

How do I know if my body is working extra hard?  Even if lung capacity appears good. 

Want to care for myself more like exercise, but so stressed by my lungs feeling different – how they hurt when walking in the cold or how it feels like I can’t breathe and then it scares me and gets worse. I need to practically find ways to handle this. And what kinds of exercise are most important?  And WHY do I feel that way physically?

How to handle anxiety about foods and meds that may help me. Like iron too. 

Stressing as I look ahead to needing surgery on my mouth.  Not sure what to do.