Italian Wool Car Coat in Navy

I am 5'9" and 180 with an athletic build so I am usually a medium in most clothing. Thus, I ordered a medium here, but to my surprise it was way too big. I am absolutely drowning in this coat, it is almost comical. I could see someone in the 6'0", 200 range fit in this while still retaining the oversized look. It was too long in the sleeves, too wide in the shoulders and too large in the chest/torso. Mind you, I have fairly broad shoulders and a pronounced chest. I purchased this along with the Oversized Herringbone Polo Coat in Cream in size medium, and that was equally too big in the same areas. I am exchanging both for a size small and expect it to properly fit the oversized look.