Always trying to lose weight for an event? I do!

Hi Everyone! I am Angela and I just wanted to introduce myself. I am 28 and just looking for new MFP friends for some encouragement. It always seems like when I have a family event like a wedding, I try to lose weight. 9 times out of 10 I will reach my goal, but then I go back to my "old" ways once the event is over. Anyone else feel like they do this? I know this is probably horrible for my body. My goal this year is to get fit and stay fit. Any ideas or suggestions of how I can change my thinking and maintain a healthier lifestyle? Thanks!