Here’s the short version: Itch uses an algorithm to evaluate projects. If it flags yours as suspicious, it de-indexes it until a human staff member reviews it.
The timeframe depends on how busy the staff is; it could range from a couple of hours to weeks, or even a couple of months in some cases. So, no one can tell you exactly how long it will take.
But in your case, it's different.
You have a game with adult content that accepts donations; currently, Itch only indexes NSFW games that do not accept any form of money.