
Why don't you try some of the free editing services like PaperRater and Grammarly? Those sites help you correct your grammar and also make suggestions regarding how to improve your sentences / paragraphs. I suggest that you use these services before you hire someone to do the editing work for you because as a student, you should at least try to get the job done yourself. Since you find it difficult to do that, consider trying the free services first. You might learn a thing or two about editing and also, manage to change/ edit / revise the content of the paper without changing your voice or method of presentation in the paper.
Use a freelance writer to edit your paper only after you have exhausted all of the "free" means of editing and you still feel that this is the best that you can come up with for your paper and it still doesn't satisfy the requirements you were given for the completion of the paper. A freelance writer might accidentally change your discussion voice in the paper but it should be for its betterment. The message will still remain the same. I would not have any worries contacting any of the freelance writers at this forum to help you out. Provided you have exhausted all means of self-editing first.
@Amanda Thanks for the tip. However, I did not encounter such problems when I was using one or the other program to help mimic the writing way of the student I was helping at the time. I also encouraged the students to use the same programs upon receiving my work in case there were some points that they wanted to alter but felt that there was no need to bother me about it. They did not report and plagiarism problems on their end. So if it was in the system, maybe they altered the paper enough to not trigger a flag or warning for them.
Personally, I find that doing hands on editing works best. Most specially now that Windows 10 offers MS Office Word with real - time proof-reading and editing. Writing these academic papers has really become more enjoyable and easier to do because the suggestions to correct, improve, or edit the content of the paper is done as soon as you complete a sentence.
That's not to say though that a second set of eyes, trained editor eyes, to be precise, is not of help in this situation. I am just saying that technology as made it easier to self-edit. The second set of eyes, will be for anything the original writer or the program might have missed in the first few rounds of drafting the essay or research paper.