@scottula, that sounds miserable. Here's an explanation Mayo Clinic of olfactory hallucination (phantosmia) that makes you detect smells that aren't really present in your environment.

- Phantosmia: What causes olfactory hallucinations? https://www.mayoclinic.org/diseases-conditions/temporal-lobe-seizure/expert-answers/phantosmia/faq-20058131

Phantosmia may be caused by upper respiratory infection and you mention that you have issues like congestion, tightness in chest, difficulty getting deep breaths, and exhaustion.

Stress certainly effects our health too, sometimes in surprising ways. You might try this online course. It was written for cancer patients, but I think it is useful for anyone experiencing stress.
– Mayo Clinic Stress Management for Cancer https://mccmscontent.mayo.edu/LSC/stress-management-for-cancer/content/index.html#/