I'm sorry you're suffering from these dark and imprisoning thoughts.
I've had some of them from time to time too - one more than the other.
Feeling as you don't belong or that you are an impostor or that whatever you create is total garbage are some things that have kept me from finishing or publishing some posts or that have came to me even after publishing something... quite often.
One I can say from the point of view of someone else than yourself - your content and creations are not shit. I see shit every day and this is not it. I know it's hard to believe, but I also know it's very difficult to accomplish things answering to your own standards.
I hope you find some inner peace and happiness into your life soon.
As for the OCD Incubation thing, of course - sorry, if you feel like your post doesn't fit in the other communities, it is welcome in OCD. All we're trying to do is grow the smaller and niche communities (and we still allow cross-posting to OCD). By the way, the communities we send people to are also curated by OCD and / or the mods and admins of the communities send curation worthy posts to OCD to curate. (In fact, I would've nominated this for a curation post, had I seen this earlier than today. Nevertheless I will see what I can do on my behalf.)
RE: Inktober day 1 - Fish