I think it's possible to be fashionable when you are larger. The key is to keep it simple. Some of the handsome big guys in my life shop online at King Size Direct. They offer a wide range of fashions for the larger guys and their prices are affordable. Stick to simple and clean lines, flattering colors for your skin tone and go for it.
I think being fashionable is more about attitude and confidence than it is about the specific clothing. Simply find a few pieces you love, mix and match and wear them with confidence. It's also nice to top it off with a great scent. You will look and smell great!!! Be proud of who you are and have a great day. :)