The thing nobody tells you about self-depreciation is that it’s a gateway drug to making other people feel shitty about themselves.
You think you’re only hurting yourself with your crappy self talk but if I complain about how bad my writing/stories are on main, say they’re garbage or that I don’t understand why anyone would read them, then what does that say about the people who love them? I’m a popular writer in my fandom and I know that objectively, I’m a good writer. If I call myself shit, then how are people going to think I feel about their work?
Making anything is hard and we all complain, but I think it’s important to differentiate between “I think this is genuinely bad” and “I think things about this need to be reworked to be better” and “I hate everything so I need to go eat something” and tweak what you do about it accordingly.
Sometimes that means tweaking your audience and sometimes it means keeping that shit to yourself entirely.