Shaving does not make the hair grow course. It just cuts off the soft fine taper of virgin hair and leaves the hair shaft with a blunt edge. Tweezing, waxing, and other methods that remove the hair from the root will cause a topical stimulation of the blood supply and cause the hair to get thicker over time. Your hair growth surge can possibly be systemic or topical growths. The trimming suggestion was good for a temporary fix.