I agree that losing 20-25 lbs in a month is an unrealistic goal. Safe weight loss is 1-2 lbs/week. I'd recommend that you calculate your daily calorie needs and just start losing now and see how far you get in a month, but don't stop there. Once you reach your goal, you'll be set and won't have to worry about losing in a hurry.
IMO that's an unrealistic goal. Even if you did it some how the weight will come back and more.
You don't need to be hungry either. But plan ahead. Buy vegetables. Cut them up and have ready like carrots and celery sticks.
When you have a big salad. Don't use dressing. A little balsamic vinegar or lemon juice is enough. You'll quickly get used to the flavor.
Drink lots of water. Take it with you everywhere.
Get more exercise. Swim. Bike ride or join a gym and get a trainer.
You'll see results! Maxy