Healthy vegetarian trapped in a fat persons body!

Hi, I'm Jena and I'm 24. I've struggled with my weight my entire life. About 7 years ago I decided to make a change and I lost 40 lbs (250-210). I felt fantastic and rode on that wave of success for awhile. I loved how everyone noticed the difference. I started caring about what I looked like and wanted desperately to lose more weight. However, since then I have had more failures than successes. Over the years, I have tried every diet and every workout regime I could find. I can usually lose about 10 lbs and then the plateau happens and I get so frustrated. But, I continued to learn a tremendous amount about nutrition and exercise. I've been vegetarian for almost a year and feel great because of it. I rarely eat processed food and buy organic whenever I can. There were times though (before being veg) that I was working out 6 days a week and eating a carefully organized meal plan prescribed by a nutritionist. Still, I had an extremely rough time losing weight. I thought maybe I had a thyroid problem, but that checked out fine. I am so sick of being a really healthy person in a fat person's body. My weight affects me every minute of the day. It controls my life and my view of myself. I have a lot going for me otherwise, yet I feel the weight cancels it all out. I'm the kind of person that rarely fails. Anything, I've ever put my mind to I have achieved. Except this. However, I think this time may be different. Since being vegetarian, my life has been crazy and I haven't been to go to the gym or monitor my calories. However, I have completely maintained for all that time. In the past, when I'm not working out or really watching what I eat, I gain. So, I really think the vegetarianism suits my body (also, I don't only eat carbs and cheese like so vegetarians! I actually eat a lot of vegetables and tofu,etc). I started using MFP on my iphone 6 days ago. I have really enjoyed entering everything and trying to stay within my 1250 calorie limit. It's been hard, but..........I've lost 7 pounds already!!! Wowsers! I think this may be it. I'm more ready than ever! I am going home this summer t to stay with my parents and work at their restaurant. They're committed to being healthy with me so this could be great! I leave in two weeks. I want to lose 15 by then. Then I have family coming into town a month later and want to lose another 10-15. More family a month later- hopefully another 8-10, and then I want to be down to 170 or less by the time I come back home on Sept 10. I can do it! Thanks for listening and I would love to share successes and frustrations with any of you.