I am sorry that you have experienced such misery. You have provided a very nicely detailed description of what has been going on. What stands out is that you have described audible wheezing, and that must be accounted for, coming either from your lungs or from your larynx. Wheezing is most characteristic of asthma but can occur in a variety of other circumstances including, but not limited to, pulmonary embolism, heart failure, cystic fibrosis, chronic bronchitis (so-called asthmatic bronchitis) and a condition called vocal cord dysfunction (VCD) in which the quality of the “wheeze” is harsher (called stridor) and occurs primarily in inspiration as opposed to the asthmatic wheeze that occurs primarily with expiration.
D-dimer elevation is highly sensitive for abnormal clotting in veins and with pulmonary embolism but is not specific for diagnosis of clotting, because the level can be elevated in other disorders (e.g., infections & chronic inflammatory conditions) and in postoperative states.
The “squeezing” feeling you are experiencing is not typical of pulmonary emboli and is more typical of heart (coronary artery) disease, with or without an abnormal heart rhythm. You might ask your doctor about that possibility.
My advice is that, the next time this happens, try to note if the wheezing occurs mostly in the inspiratory or the expiratory phase of breathing. Confirm with your doctors that the CT scan was performed specifically to detect pulmonary emboli and even after further review was normal/negative. Ask your doctors if the diagnosis of VCD (see above) might deserve consideration. If so, pulmonary function tests (that when normal do not rule out the diagnosis of asthma) should be repeated with attention to the inspiratory phase of respiration along with direct examination of your vocal cords. Acid reflux can be a cause of VCD.
Finally, having noted your belief that, “it’s not anxiety”, I would still suggest that it might be and that many of the symptoms you’ve experienced have been associated with a condition associated with anxiety, called Panic Attacks. You might want to ask your doctors about that possibility.
Good luck
Sounds to me like it could be exercise induced asthma or allergic asthma. Spirometry can be absolutely normal between attacks, but show typical changes after exercise/ provocation by whatever you are allergic to. Pollen counts are often high in the early morning and worse if window is left open. Perhaps you can buy/borrow a simple peak flow meter to test your peak flow at various tines during the day. If there is 15% reduction or more when you have symptoms that confirms the diagnosis.
Did you use a condom with sex? If so latex allergy could also be a culprit. Many beds also have high latex content.
I made a mistake. I think it was a spirometry test that I did at the doctors office, not a pulmonary function test. So I'm pretty sure I've never had a pulmonary function test. The spirometry test was normal.