I really had to address how I treated my art and how I critiqued myself to also address my Imposter Syndrome. I would be so critical and say things like "this is bad. this is so terrible" just grand sweeping statements that are...genuinely not true. Habits you pick up in art school where you have really intense critiques and occasionally really toxic professors. Those statements about art also sweep into how you talk about yourself, eventually "I'm so bad. I'm so terrible. Why would anyone hire me?" and then that goes directly into Imposter Syndrome.
So honestly, I had to draw some lines for myself--I had to stop talking crap about my art (especially online) and I had to learn to critique myself without tearing myself down--constructively, about my own art.
If you are waiting for subscriber numbers to prove if your Imposter Syndrome is real or false--if you are waiting for a certain job to prove if you can become the artist you want to be--then you're at the mercy of fleeting algorithms and job economy, which is not the same thing as being a good or worthy artist. It has to be a conviction you have despite whatever happens job wise or numbers wise (especially since jobs and numbers have a billion different factors attached to them) And while we can learn from these numbers and learn from when we might get fired or don't get the job we want--that learning is for our improvement, not for us to say "well I knew it, I always knew it, time to just give up"
Oh, and another thing--I think it helps to learn how the internet works? Not everything you make will go viral. In fact, out of all the stuff you'll make, probably very few of it will. And, if something goes viral, it's perfectly normal for numbers to stabalize again. It's really common for one post to end up with 1,000+ likes and then in later posts it's like...it never happened. You get 2 likes on everything else. This isn't that people were like "oh this person is actually terrible" it's just that...this is how the internet works. Not everything you make will be a banger, so allow things to just be what they are, and keep creating knowing that at least one of those things will be.