Does anyone have any tips for losing weight before the wedding (to lose inches around the belly area in particular)?

Getting married in June and panicking!! I’m size 18 and recently I have been quite unwell. Instead of losing weight I have put on weight before my dress fitting due on Thursday. I am then being refitted again later this month. Does anyone have any tips for losing weight before the wedding (to lose inches around the belly area in particular)? Also… I’m in a full time job that means I leave the house at 7am and return at 8pm so no time for the gym other than on days off. Thanks!