Hi i have a similar issue yet, I am really really worried. Basically submitted my dissertation on monday - 15,000 words and then had a horrible feeling I had forgotten to referanace something. Put it through a plagarism checker and its is 2/3% plagarised. (i think about 4/5 sentences In seperate areas I havnt referenced properly). I know I should have done this before hand but didnt really know it existed. Raised concerns to my supervisor, academic advisor and student welfare office. All said I would be ok but might loose a few marks. Still really worried and cant concentrate. Can someone ease my mind/ please say they have been in the same situation. My acadmic advisor said look they know its not on purpose, people make mistakes. Just so annoyed at myself.