Writer's Advice and Feedback Group discussion

One of my books received a review at Amazon, saying "A good novelization of the history of Spanish physician and theologian Miguel Servetus (...) But the language is somewhat halting - presumably due to the translation."
The reviewer is probably right. The book was translated from Portuguese. The translation is good, but the English language could certainly be improved. Can anyone give me an idea about where to find professional help to solve this problem?

Have you tried hiring a translator?

Iesha (In east shade house at...) wrote: "Have you tried hiring a translator?"
Yes, Iesha, I hired a translator. The problem is the translation apparently halts a little.