I get an aggressive cough every year, in december, february or april. This cough is so bad that I feel like I might die from it. I was tested for allergies and no allergies were found. I believe the cough might be associated with emotions but have not been able to identify the emotion.
While certainly physical, mental and emotional components of a person are considered in Chinese Medicine, something that is as finite as you are describing is unlikely to be solely from emotions - unless possibly an anniversary of an emotional event.
Generally speaking the “lung” system is involved in cough and/or cough from emotions - for the basics of this system you can read “My Lungs Are What?”.
Realistically you would do best to consult directly with a practitioner in your area who can get into all of the relevant personal details, relevant tests, etc. So all I can say is that generally speaking Chinese Medicine does well with cough (related patterns, possibly treatments, etc. are on our “cough treatment section”).
Regarding the allergies, just because your allergy tests didn’t show anything of note, that doesn’t mean it isn’t there. You, however, would often have an instinct on whether or not that was the background of your issues.
The other main aspect for something like this that is less obvious is that it is from the digestive system somehow. This could be environmental impacts on digestion, seasonal/holiday impacts, seasonal food impacts, or any combination thereof - as well as, of course, emotional inputs - see also “My Spleen is What?” - for relevant basic details on the “spleen” system.