In general, a safe weekly weight loss would be 1-2 pounds per week for someone with a lot of weight to lose. The closer a person is to a healthy weight for their height (less to lose), the longer it takes to lose.
Also, if a person has been a yo yo dieter, each time they lose, gain and relose that same weight, it gets harder and harder to take off. So, let's say it took 6 months to lose 25 pounds the last time. It could take up to a year to lose that same amount. Each time we lose weight and regain, our bodies become more efficient at holding onto that weight. In an ideal situation, once a person takes the weight off, they need to keep it off. Which isn't easy.
What to do ? Instead of being ambitious and trying to a 2 pound loss per week, why not try for a one pound loss. Keep in mind that there will be weeks you don't lose. There will even be weeks you gain. And that doesn't mean you're doing anything wrong. losing weight isn't just about eating less, it's about establishing healthy habits we keep for life, not the amount of time it takes to lose.
So, I would suggest a one pound loss per week instead of 2. See how your body responds to the changes. This will take time.