Almost every review has been terrible

I’m at the point with this series I don’t even know what to do anymore. Every recent review has been complaining about errors yet I’ve had it looked at twice professionally I’ve even gone back to edit after publishing it a few times. I’m utterly confused on what to do, I can only edit a book a handful of times before I give up. The thing that kills me is that my first ever written book, has great reviews! And I didn’t even edit it as hard as I had with this one. I’m wondering if fantasy readers are just mean? Every fantasy book I read I notice awful reviews too, should I bite the bullet and hire another editor to go over the book or should I leave it as it is?

I’m actually so turned off I don’t even want to finish writing the series because I feel like a pure failure. The book currently has 2.9 stars which is insane because in the beginning it was getting good reviews. It’s also been out for almost two years and just began picking up which is why I’m thinking if I need to re-edit for what feels like the 100th time.