The OP says that he was struggling and needed some help. In my experience as a writer, if a student has been performing poorly throughout a given module and demonstrates some 'spontaneous' remarkable recovery, the type of consequence Trouble is experiencing should not necessarily be all that puzzling. Here's an illustrative example:
Recently I had to put together a lengthy market entry analysis for an international student's final, a paper that was the culmination of a six-segment module. Segment 6 was based on the information from segments 1--5. The student handled the first five segments without my assistance, and when I went to review them for the sake of writing the 6th segment (the final comprehensive document), I discovered a number of errors in the strategic analysis they conducted in segments 1--5. I corrected those errors in the final paper. Despite being well written, the professor accused the student of plagiarism, and the case is still pending.
My personal advice to my client was for him to urge the professor to submit the 30+pg document to turn-it-in, because otherwise there was no evidence of any plagiarism. I'm not certain what your circumstances are like or what you have already admitted to your school admins, trouble, but my client has been very steadfast in denying any plagiarism whatsoever. However, note that he could only be confident about doing so because I confirmed to him 100% that none of it was plagiarized. I guess my advice to you is to see if you can get in contact with the actual author of your paper and to try to ascertain whether or not they plagiarized any parts of it. If:
1) Your writer did not plagiarize;
2) Your writer is willing to work closely with you through this dilemma; and
3) You have not already admitted any wrong-doing to your school admins,
then you might still have a chance.
Hope some of my info helps you out, Trouble. If you get a chance, please try to post in greater detail about your situation and I will do my best to offer you some advice that is more helpful to you specifically. I have some experience with these types of situations, but it is really case-specific, so the more info you provide, the better we can help you.
Best of luck, mate.
-ACE