You are not going to lose that amount of weight, so it is best not to eat diet foods because you can spur a weight gain with them. You can become more muscular, though, and that would help you look much better at the same weight. Overtraining after a sedentary period is a risk (I just hurt my foot from walking too much in Vibrams), so "hitting the gym" is dangerous, but doing things slowly and especially going for safer exercise, such as swimming, will make you more muscular and will improve your posture. Posture is very important to looking good. Set reasonable, attainable goals and pat yourself on the back all the way. Using the approaching wedding to stimulate yourself is fine as long as you realize that you are in for a long journey; using the wedding to punish yourself with unrealistic goals is not OK and you are doing the latter.