Here's something you don't hear people bragging about: "I'm a real real downer with my music".
Although this is not a sought accolade, it's one that applies to me, and I think many creative and/or introverted people tend to experience inspiration from dark and sad places in everyday life a lot of the time. And while it may not be a coveted characteristic, I do think that bringing some of that melancholic mindset into your life and music can be beneficial on multiple fronts.
First off, everybody has times where they feel down. I don't care how happy you are, how many positive/uplifting/smiley instagram posts you make, how annoyingly smiley you are (just sayin), nobody's immune to the blues. That makes tapping into the "dark side" something that's relatable, and I know I've felt the powerful effects of feeling the same way as a singer singing about how bad life/love/etc is.
Also, there's something painfully human about it. I remember the first the I heard Adele's "Someone Like You" on the radio, I was tearing up by the 2nd chorus. I don't cry easily, so that's telling of the kind of connection songs like that can give to your emotions
Lastly, often our negative feelings stem from something we want to change - whether in our selves or in the world around us. And the desire for change can be a powerful catalyst to get people to feel & understand and get on board with what you're so passionate about. So acknowledging those low places in our minds, hearts, and souls can be a first step overcoming them, or at the very least realizing that we aren't alone in those feelings.
I don't know, maybe I'm just trying to defend my 80% sad/depressing/angsty songwriting, but I feel like there's something to be said about taking the good AND the bad. And let's face it, sad songs, even though they make you cry with all the feels, will always be a mainstay in music.
So even when I'm singing a downer, sad, emotional song, I'm still singing.
I'm still singing.