38%? I’ve seen people get away with 70% 
If you are accused, you have a right to go in front of a committee to defend yourself. Most colleges are more lenient the higher you go up the chain for plagiarism, unless the paper is literally a duplicate.
You should go to the Dean of Students and bawl your eyes out. You should have a right to review the results of the plagiarism program.
Except: If you worked with someone else in the class, that’s much worse than random internet references.