That's what this website here is for.
That's absolutely right. But still there's no fix for attitude and enthusiasm.
Let me talk about book covers, to avoid the more recent hot-button topics.
I've studied marketing, and I've done some photoshop projects before. I'm not an artist, but when someone posts a book cover, I know enough that my first thought is always "How are my eyes tracking through this image?" That's a question most people don't even know to ask. We have a couple of experienced artists here, and others who have come and gone, who give far more valuable insights. Yet, sometimes people resist the feedback - I don't mean that people just disagree, but that people don't even understand the feedback, and resist the idea that there even are underlying principles on which that feedback can even be given.
That's just an example. Most people aren't too bad with the cover art because they know they aren't artists. But there's a sliding scale of attitude to all of these steps - book covers are probably where people resist the least, critiques where they resist the most (admittedly, not without reason).
We can offer some guidance, but we can't easily offer something that will reshape your entire mentality towards the project, the way that finding a publisher can. The drive needed for self-publishing has to come from you. And it has to be strong enough to get you through each one of the hurdles, not just the first few.