Thank you for your reply,Gabe.
Iron deficiency does not seem to be the issue as my iron levels have tested normal. I’m taking iron supplements now in any case since the anemia diagnosis. My breathing issues continue to kind of come and go. Yesterday I felt fairly normal for most of the day and was optimistic I might be getting over whatever this is. Then last night the tightness in chest returned (coincidentally after one drink at dinner??) and the labored breathing persists this morning.