Having a hard time.

Just starting weight lifting could have two effects that are relevant here: One would be water retention masking fat loss on the body weight scale, the other would be that some people find certain types of exercise especially fatiguing, and lifting can be one of those.

Even with the probable water weight in the picture, as was pointed out you've seemingly lost up to as much as an average of 2 pounds a week. That would be super-fast loss for someone of 128 pounds aiming for 115. Super-fast loss can definitely make a person feel burnt out and beat up.

Even a pound a week is fairly aggressive at 128, IMO, honestly. Especially for someone with a busy, stressful life whose current weight shouldn't be a significant health risk, I'd suggest something like 0.5% of current weight per week as a loss rate. That would be 0.64 pounds a week, so somewhere between half and 3/4 of a pound.

If 1480ish is estimated to give you a pound a week, that implies maintenance of 1980ish. Hitting right on an estimated 0.64 pounds per week, the calorie goal would be more like 1660. Would that help?

But that's just an estimate based on a statistically average person, right? You may not be statistically average. Most people are close, a few a bit farther off (high or low), and a rare few are surprisingly above or below average in calorie needs. (I maintain on 25-30% more calories than MFP and my good brand/model fitness tracker estimate, for example.)

We're assuming part of your 8-pound loss was water weight, so we don't have exact figures. But if you lost 2 pounds of fat a week eating around 1480, that would imply your maintenance calories could be more like 2480. That's possible, but it's hard to tell: Not enough solid data because of major changes in your eating style and exercise types/level.

For sure, if you're feeling burnt out and beat up since cutting to this calorie level, and there's no other obvious reason for it, that's a danger sign. Even if you've only lost a pound (or less) of fat per week, please note that any calorie deficit is a physical stress, and new exercise is also a physical stress. You have a busy life, which implies pre-existing stress. That's stacking stress upon stress, and that's maybe too much to take on all at once?

At this point, I'd maybe suggest you start eating at some higher calorie level for 4-6 weeks (whole menstrual cycle if you have those, to compare body weight at the same relative point in at least 2 different cycles), and keep your eating style/exercise activity reasonably consistent over that whole time period, too. Whether you lose, maintain or even gain a small amount over that time, that would give you a much better reading on your actual calorie needs. Then you can dial in a sensible loss rate with more confidence in the numbers.

The personal arithmetic (vs. just calculator estimate) is pretty important . . . very important for people who turn out to be statistically unusual. I lost too fast by accident at first, because of the under-estimates of my calorie needs. I felt great, energetic, not hungry for a while . . . until I hit a wall, very suddently felt weak and fatigued. It took multiple weeks to recover normal energy and strength. No one needs that!

Hi, awesome discussion. Just would add that water retention can happen towards end of a monthly hormone cycle, followed by a woosh off when the cycle ends and begins again. Usually, i would see about day 3 month compared to last month would be a weight loss rate that matched the calculators over 4 weeks instead of the ups/downs in between that were more a mystery..
. And that is if/when my eating and movement was consistent acrpss the month too.

Let us know how you're doing and if it clears up for you.

Sounds like a reasonable adjustment