Just drink protein shakes to jump start weight loss

I agree with others that it's not a great idea for the reasons they've given and others . . . but will say this, too: If you decide to try this, please use "meal replacement shakes" not "protein shakes". A short stint on shakes only won't kill you (probably), but do choose shakes designed to have a reasonably complete nutrient profile, not just protein.

At 30, you're young enough to still have menstrual cycles. If that's true, 3 weeks isn't a giving your new routine a fair shot. Some women only see a new low weight once a month, because hormonal water retention cycling can be that weird (even though that's not the most common pattern).

On top of that, it's common for anyone to see some water weight loss at first, then water weight rebalancing that looks like regain after that for a couple of weeks, so anyone (not just premenopausal adult women) ought to be looking at 4-6 weeks of consistent experience data before making a change.

Are you actually calorie counting? If so, how many calories are you logging on average daily? Twenty minutes of walking videos 3 times a week is a good thing, but realistically the number of calories it would burn isn't huge in the big picture; and "cutting back on eating" won't result in weight loss unless calorie intake gets meaningfully below total calorie burn. (That's true whether you're counting the calories or not.) "Changing foods" has no direct impact whatsoever on weight loss, though positive changes can help us feel more full while losing, or improve nutrition so be better for health in the long run.

Have you been weighing yourself under consistent conditions, like first thing in the morning after bathroom and before eating/drinking, in the same state of (un)dress? That's the best way to get a picture of weight loss rate.

Most of us find that our bodies fluctuate by multiple pounds from day to day because of perfectly healthy, normal changes in water retention. If you only weigh in once a week or every few days, you can accidentally pick a low day at first, then a high one the next time, and be misled.

People who find weigh-ins very stressful may need to weigh less frequently, but for those who aren't stressed, daily consistent weigh-ins will help create familiarity with the totally-normal up and down patterns (that will gradually trend downward if actually losing fat). Fat loss plays peek-a-boo on the scale with water retention fluctuations, but it's fat we really want to lose, yes?

That's part of the reason why a 4-6 week (whole menstrual period) average is a better gauge of weight loss than a shorter time period.

I'm not trying to be mean in saying all this. If you actually lost 2 pounds in 3 weeks, that's a good thing, pound and a half average per week . . . by the end of a year, around 78 pounds, eh?

There are quite a few of us here (me among them) who got through losing to a healthy weight, are now long-term maintaining, who would say that the best route is slow and steady loss that a person can stick with long enough to cause a meaningful total amount of loss.

"Lose weight fast", treating it like a fast project with an end date, can be a trap. It can be that a slow but manageable loss rate gets us to goal at an earlier calendar date than some extreme approach that includes periodic "off the wagon" overeating or "cheats", or makes a person give up altogether.

You can do this. It's going to take time and patience. It doesn't necessarily require extreme tactics, I promise. Extreme tactics can even backfire. Give it a think.

Wishing you success, no matter how you decide to proceed!