Unfortunately there are very few chances from what I have understand. Steam is worst with devs that the justice is with criminals... they have appeal. Steam.... basically doesn't.
and the policy of steam is very very weirs with nobody really knows what the rules are. From what I have understand depends who will review your game (i understand there's somebody named Mary who likes to ban AVN for whatever reason)
also in many cases they don't tell you what's the problem. and you can't "fix" the issue once is banned. I haven't put anything on steam, but that's what I have heard. But It's weird that the demo passed, but the game didn't. the ether change the reviewer of the game contains something weird? From what I know only realism or pedophilia are reasons for banning. And pedophilia is "looking to young even if you say it's 18 yo+" So even the graphic style might be and issue. It would be easier if those idiots talked but here we are... Some reviewers seam to want to ban a game and they just look for reasons. That's the biggest issue with steam from what I have heard.
Anyway I really hope you can unban your game, but i doubt that it's possible.
You should think of alternatives: patreon (hate them but...), subscribestar, the guy that makes Fetish Locator has a store, etc. itch.io is not known enough unfortunately.
I wish you the best of luck and don't forget to announce on f95 what you have decided.
PS: If by a miracle, the game gets unbanned, will the people who buy the game here get a steam key? 10x