It sounds like you might be looking for an editor. A professional copy editor can be found here: https://www.sfep.org.uk/about/faqs/what-is-copy-editing/
You might be able to search "copy editor" and find some other resources.
If you can't pay someone for editing services, then you'll need to find someone who's invested enough to do it for free, like a co-creator. I feel your pain in that regards. I'm also trying to put together a new RPG, and while I've gotten great feedback in my playtest games, I haven't been able to get anyone to invest more time than just playing the game. Which, hey, is fair. It's not their project.
Are you open to selling your game to a publisher? They've usually got resources like editors and artists who can give your game the proper polish you need to finish it up.
I am not quite ready for an editor. I need opinions on the rules and such, impressions from potential players. After my next round of playtesting, once I have implemented all the stuff that needs to be corrected/updated, then I will likely be in the market for an editor. I don't mind paying for one, but for something of this length its over $1000, so I only want to pay for it once. I have to be in the right spot to make it count.
I would totally sell it to a publisher, but I think this game is so different from what is on the market that I doubt there would be one willing to take it on.