How many calories do you reduce your daily intake, to speed up your weekly weight loss?

My perspective: You don't actually know your weight loss rate until you've stuck to one calorie level, eating and activity regimen for at least 4-6 weeks. Women who have menstrual cycles should compare body weight at the same relative point in 2 or more different monthly cycles.

Short of that, one would be over-reacting mostly to fluctuations in water weight and digestive contents. Even fast fat loss is a few ounces a day. Water weight and waste in the digestive tract fluctuate by multiple pounds from one day to the next, playing peek-a-boo on the scale with those much smaller fat changes.

So far, it sounds like you've lost 4.5 pounds in 3 weeks. That's a good loss rate. Don't drop calories further now would be my advice.

Your ID sounds male. Men shouldn't be eating less than 1500 calories daily unless quite short of stature, very inactive, older . . . and with a track record of multiple weeks of needing to eat less than that on average in order to lose. Even then, it's iffy.

IMO, trying to lose more than 0.5%-1% of current weight per week, or cutting calories more than 20-25% below TDEE, is a poor plan unless severely obese and under close medical supervision for deficiencies or health complications.

Fast loss can become unsustainable, limits adequate nutrition, can increase health risks, impair exercise performance, trigger fatigue or weakness, cause hair loss, and more. While bad results aren't guaranteed, odds of negatives increase with low calories. There's no way to get adequate nutrition on too-low calories, among other issues.

Also, guess what? Cutting calories too far stresses the body, and stress can increase water retention. Don't create a cycle of stress, water retention, cutting more calories, causing more stress. That's not a path to thriving.

The big prize in all of this, if you ask me, is not weight loss. It's reaching and then staying at a healthy weight forever. That latter happens when building new, relatively happy (as least tolerable and practical) new habits. Cutting calories repeatedly or deeply for fast loss isn't very compatible with finding those long-term new habits.

For now, I'd suggest you go back to MFP's original calorie recommendation (unless it targets a faster than sensible weight loss, 2 pounds isn't right for everyone). Hang in there, being consistent, for 4-6 weeks, then look at average losses to adjust, based on the assumption that 500 calories a day is a pound a week.

Just for context, where I'm coming from: I lost from obese to a healthy weight at age 59-60, while severely hypothyroid (medicated for it), in a bit less than a year after having been overweight to obese for around 30 years previously. I've been at a healthy weight for around 8 years since. That's the experience and perspective that leads me to give the advice above.

I'm wishing you success: It's worth the effort.