Usage of 'morbid' and 'morbidity' in non-medical contexts

I have a question about the liberty we can take in using the word 'morbid'.

Generally speaking, what I understand the word to mean in a medical context is a state of sickliness. That's just how the population is and life goes on.

I have the following example wherein I used the word morbid in a non-medical context:

Last Christmas, the family woke-up to the sound of loud arguments coming from Jim and Jane's room. We all just stayed in bed till it was time to get the lunch ready for the family. Having lost the entire morning, I decided to just order pizzas for the day. Jim and Jane seemingly didn't find any resolution to their fight and their bad mood affected all of us. It was disappointing to spend the Christmas lunch and dinner with a sense of morbidity in the air. Forgive me for not wanting that to happen this year.

Interested to know your views. I actually find it interesting to use words in ways inspired from different topics altogether. I feel it can be quite impactful without being obvious.

Even coming from a medical background in childhood, I am nevertheless accustomed to this use of morbid and morbidity, despite the medical use or the connotations of death.

morbid =

abnormally susceptible to or characterized by gloomy or unwholesome feelings

Merriam Webster

to be gloomy on Christmas day is indeed abnormal relative to most people's expectations of the festival. I believe your usage to be justified.