Sorry you're going through this, Rennon.

It does...though, it does get better. Eventually. The hardest part is being to stubborn to let it win, and It gets harder, every time.
There are life lines though. Friends, Family, even pets. Even if you can never let those words let you enjoy life. You still have your pet. And who's going to take care of it when you're gone?
So you can't go. Not yet

I know this monster. It lives within. You can fight it, stand up to it. And you will win, and come away stronger. It has helped me to find something to divert your attention away from the self pity. In your case, possibly your art. In my case, it has become a weekly trip to the bowling alley, (I'm STILL a terrible bowler) and tinkering with my electronics.

Consider also, that at least part of the depression could be seasonal. I suffer from seasonal affective disorder, where I get depressed right around end of December thru January. I get listless, depressed, lazy to the point of lethargy.

As Nietzche said: "That which will not kill me makes me stronger." (If you want to impresss your friends, learn it in German: “Was mich nicht umbringt macht mich stärker."

Keep on keeping on!

I wanted to add something, but you covered it - even down the the last line! Well said!