Hello and thank you for asking about this question…
I am a self-taught digital artist who loves to draw to express my thoughts and emotions.
Surely the state of your art style and how you create your art (or any form of arts and crafts) is heavily influenced by your emotional state.
In my personal experience, the times I have found myself feeling stuck, stressed, depressed, and heartbroken have been the times where I have produced some artwork which I am very much proud of.
You might also agree many songwriters (and the singers) have written (and sung) great songs to express the emotions of pain, love, joy and whatnot!

Coming back to my own experiences, when things are not going quite well, I try to draw what I am feeling, and the colour combinations nicely incorporate the negativity surrounding me and come into my hands naturally! For eg. while feeling depressed or sad, along with a gloomy expression of the character I have drawn, more often than not, the combination of purple grey and blue is used to highlight the negative emotions which is overwhelming the character.

Similarly, my happy experiences are highlighted by bright colours like yellow or golden colours along with comforting and happier (cuter) expressions.

Many people find it easier to convey and express their feelings through their artistic skills because it becomes quite difficult to use words sometimes, and that is why art is truly a beautiful medium of expressing emotions.