If the reader thinks something you write is unclear then it is, by definition. Expect criticism from your faculty advisor. Most people's first drafts are jammed with elegant variation, traffic signals, illogical sentences, nonsentences, misquotations, boilerplate, monotonies, and jingles. Don't expect to write easily all the time. Writing, like any form of thinking, flares and fizzles like a fire.
Irrational cheerfulness is hard to teach but good to learn for any serious work.
When you find that you really don't understand one of the suggestions your instructor made, don't hesitate to return for clarification. When style questions stymie you, consult your instructor, a friend, or visit The Writing Center in 307 Olin Library. When revising pay special attention to your introduction. Start the paper with a substantive, interesting thesis or question, not a boring one. This paper discusses the evidence for a large effect of monopoly on income.