This is the ugliest thing a person can ever feel. I've went through that, and probably still is undergoing it. But I just try to let the positivity overpower it, like talking it out, watching videos (of my biases) and stuff. I also try to make myself busy, so that I forget about being sad and feel pressured instead (idk, this works for me... kinda). Ah, you don't have to push yourself to write fluff fics. Write angst, since you could relate to it, and it will send the readers better emotions since you wrote it in such a state. I did that, too, when there was a certain point in my life I was really down.
I know this probably won't help or something, since our minds might differ in more ways than one. But I do hope you feel better soon!

I really know how u feel my friend.. it's happened to me.. always ! The only thing u need to do is try to calm urself.. Think why it's bother you.. comfort urself and try to let it go.. stay strong and please don't be sad always :')

it's pretty much just a phase. i been thru that a lot, i mean quite often...what i do i try to block the negativity outta myself and ignore the bad thoughts. don't fall back to the dark hole. i know it's hard but please stay strong. i know you can get thru it, it may be hard rn but it will be better.

You're just same as me. I've a depressed so it's quiet normal for me