Hey just so you don't get stuck with this, specifically for the mental illness and cultural stuff: ChatGPT will spit out what is said the most about a subject, and the words most associated with the name of the illness or the country of origin of the culture.
Thus, it's going to be heavily biased for the mental illnesses that have strong stigmas around them and the cultures that are often stereotyped but rarely deeply explored. It is also heavily biased depending on the questions you ask, which can be leading questions without you realising it, based on your bias. Though it's been programmed to steer clear of obvious hate speech, it's been known to be surface level on spectrum disorders like autism to the point of caricature sometimes. It is also capable of inventing studies out of thin air (cf the lawyer who got disbarred for using ChatGPT instead of PACER and ChatGPT just invented a pdf of court cases).
For accurate info especially on divisive and stigmatised subjects, you'd be better off using Wikipedia and scrolling through the footnotes, seeing as you'll have to double check all the info the AI spits at you anyway. You have a wealth of diversity here on the forums, and many people who would be perfectly happy to inform you about their culture and life in a way no AI ever could. Don't spit in their faces by insinuating that their humanity can be replicated by predictive text.
The pressure excuse isn't good. Everyone here has commitments and stuff that needs to be done and pressure in life. You should love your comic enough that making it is what feeds your soul, and by using AI for the cover you've made an insult to the rest of your hard work by putting it under a neon sign that says "I'm too lazy to actually care about artists". If you are under pressure, you just don't publish the comic until the cover is ready, simple as that. You're not under contract for this, you don't have deadlines, you can post a week later and be fine.
Even taking away the ethical problems with genAI you've shot your entire comic in the foot by having the first image people see of it be some cheap approximation of humanity, and it's false advertising because it's not the style or actual quality of what's in the comic. Even people who don't care about AI will feel like you lied to them, no wonder you aren't getting views. This hurts you, your comic, and the art community as a whole, and yet you still don't care enough to decide to do the thing that is better for everyone.