Dear Leah,
Best wishes! I had excellent suggestions and support from the nutritionist affiliated with my primary care physician. Try to get a referral. The winning functional suggestions:
1) Attitude: Recognize that mild hunger, not sated fullness, is our "natural" state, the circumstances our bodies evolved for.
2) Keep a food and exercise journal: You don't have to show it to anyone, but the mere act of logging what you actually eat, how your feel about it, and what you're doing for exercise has been demonstrated to dramatically improve the odds that you'll achieve your goal.
3) Eat smaller portions of whole foods, with a mix of protein, fat, and carbohydrates, in that order, on average. Exceptions are ok, as long as they're exceptions. Use smaller plates. Don't snack. Eat mostly protein and fat for breakfast, your biggest meal at lunch, and a salad for dinner. (This is hard as a vegetarian, but I manage.)
4) Do weight bearing resistance exercise more than cardio. Do it every day, for whatever length of time your can manage. If you find yourself consistently doing pushups at midnight to meet this, consider switching your schedule around to do it first thing in the morning. It improves the day immeasurably to have it done and out of the way.
5) Choose your goals wisely: A single weight goal is not a good target in and of itself. BMI is little better. Fitness goals, like a number of pushups, a distance run, a threshhold in yoga, a waist-hip ratio, these are more meaningful in a physical cause-effect correlation to metabolic diseases.
6) Forgive yourself as often as you condemn yourself. Start again, clean slate, from your new beginning. It's ok. Really.