1) Definitely remove the fentanyl part per other comments above.
2) Work on eliminating the word "I". Overuse of it is quite distracting. And very few actually achieve success as an individual - more often it's part of a team.
3) Choose less bragadocious words. Instead of dominating chemistry, excel at chemistry. You want to sound confident, not cocky. There were a few other words to rewrite as well.
4) You say you want to be a supervisor but have shown no aptitude for it. Being boastful certainly doesn't help your case here. You haven't depicted any leadership skill development in your essay. Either rework the tail end to reflect your potential as a leader or eliminate the idea of being a supervisor from the essay.
5) The answer to why not med school isn't very clear. After re-reading the answer several times, its still awkward. Simplify the answer. But to be honest, why are you even making that statement? It may be a better use of your word economy to focus on what you bring to the table. Undoubtedly you will be asked why not med school during an interview - don't waste time on the answer here. Remember that the reader has one objective - to classify you as a "must interview" candidate. Ask yourself if answering why not med school actually helps you here.
If it were my essay, keep the top part about your injury. Rewrite the paragraph about why that led you to pursue pharmacy. Delete the part about med school. And focus on your academic and person growth as well as achievements in your pursuit of pharmacy with a summary at the end about why those achievements demonstrate your passion, aptitude, and admission to pharmacy school.
