I'm 42 5'5" Tall And Weigh 250 Pounds How Can I Lose 3 Pounds A Week?

It is best to lose no more than 2 lbs a week to keep it off. Exercise, eat healthy snacks and meals, no junk food or empty  calories, don't skip meals, don't eat when bored or watching t.v. Unless it is celery or carrot sticks, don't eat after your last meal of the day, eat smaller portions, and drink lots of water. Hope this will help you.

That's overambitious and you'll likely put it back on again when you come off the diet. Better to aim for 1-2 lb a week, and a more sustainable food intake and exercise programme. Having said that, you are so grossly obese at present, that anything approaching a sensible lifestyle should have the weight dropping off pretty fast for the first 50lbs or so. You are classified as obese with a BMI of 30, yours is almost 42, so you're pretty much twice the woman you should be.