I'm going to throw something

You just said it..you log everything but don't WEIGH it??
Chances are, you're eating more calories than you should.

try to focus on long term changes, not day to day changes. Day to day changes are water weight, not fat. However the long term changes will be changes in fat. Fat is lost and gained slowly. losing or gaining 4lb overnight is water weight.

Have you been tracking and logging consistently for several weeks? If so, has your weight stayed the same or gone down in that time? If it's gone down at a rate of 0.5-2lb a week during that time (averaged out over that amount of time, even if it doesn't look consistent week to week) then the plan is succeeding and keep going, and try not to let day to day weight fluctuations mess with your head... for most people it's better to restrict yourself to weekly weigh ins, in the same circumstances each time, e.g. same day of the week in the morning after using the bathroom before eating breakfast, and don't choose a day right after a cheat meal or a heavy day in the gym (these things can cause an increase in water weight). That really helps you to see the big picture.

if your weight has stayed the same after several weeks of consistently tracking your calories, then the most likely explanation is that you're eating more or burning less than you think you are, e.g. guessing portion sizes or overestimating your exercise calories or activity factor. The best advice would be to try for a couple of weeks where you do make sure you measure and track everything that you eat, including condiments, i.e. everything that goes in your mouth gets tracked. If you think the fitbit might be overestimating your calorie burn, try eating back only 90% of your exercise calories (or if you're doing the TDEE - x% method, subtract 100-200 cals from your TDEE and calculate your calories again with the new TDEE) - then try this for a couple of weeks and see how it goes.

If you have recently started an exercise programme, this may have caused your muscles to retain water (part of the growth/repair process, and it's a good thing) which can result in the scale not budging even though your clothes feel looser and you're losing inches. If that's what's going on, keep doing what you're doing and you'll see the scale weight go down after a while. Loss of inches, looking better in the mirror and clothes feeling looser are signs of fat loss, even if the scale doesn't show it (yet), those things should be seen as more important than the number on the scale.

Weigh everything and be honest about what constitutes exercise. For some people cleaning is exercise, for others it's not a good logging decision. I'm unCertain where you got your loss calories of 2100, but for a woman that seems a bit high unless its your gross total and you're not eating back exercise calories. If you're going to make this work you have to be honest in your log, which includes measuring your food) and you need to be honest with yourself. I recommend you try your tdee.

Thanks people.

According to the WHO calculation for BMR, my BMR is 1836 (formula provided by my doctor), and the factors for TDEE are 1.3, 1.5 or 1.7. Therefore, my TDEE at lightly active (1.3) would be 2386.7, moderately active 2,754, and highly active 3,121.

I'm probably going to retreat back to the 1500-1800 gross range, even if my net calories have almost never gone above that range (with two notable days of late) and keep walking the 5-7 miles (all steps taken, plus a 1.6+ mile walk most days) and see what happens with that.

And yes, I've lost inches. Just frustrated.

Thanks again.

You didn't say whether the 2 lbs was a sudden gain or a gradual one. If it was sudden then it's water retention and there may not be a reason to change your calorie intake. If it was gradual my first course of action would be to start weighing your food. Cutting 600 calories (from 2100 to 1500) is pretty drastic. If you do decide that cutting calories is the best option, why not start with something in the middle, say 1900?

Girl-
Okay let me explain something I just learned about our lovely bodies. First we are women, and our hormones change at the drop of a hat. Weight loss stimulates changes in hormones... awesome.... not.

We've been doing this for a while, and having great success. Its awesome, but here's one thing. Our bodies have a balancing act to find. They survived off crap and an abundance of calories but hardly any nutrients for a very long time. A balance was found, our bodies learned to function with what we were giving it.

Now, change it all! I know I eat WAY healthier than I have in two decades. So I have two decades worth of acting one way for my body to unlearn. It has been for almost five months for me, I cannot expect my body to just scrap what used to work in such a short amount of time. For example, for two decades I drank little to no water. My body would hold onto that little water it did get because I never gave it enough. Now I am drowning myself in water. But it just got warm outside and last summer I didn't give my body enough water. So if patterns hold, my body thinks it won't get enough for the warm weather so its holding onto every last little bit it can. Solution, drink more water, and be patient. I gained 7 pounds in two weeks and yesterday it all came off. Sucks I lost 2 weeks worth of losing weight, but 2 weeks compared to 2 decades... I'd rather lose 2 weeks than 2 decades.

Also hormones, weather, activity, soreness, muscle growth, all play a part in what the scale says. I have a friend who lost 200 pounds in two years and this is what she has said to me. "Sometimes my weight would fluctuate by 20 pounds in a month. I would freak out, but continue to push and keep at it. It would seem like forever before that scale would go the right direction. But it always did...eventually. Eat healthy, drink as much water as you can every day, and be patient."

We are not only teaching ourselves how to feed our bodies and rid ourselves of food issues, our bodies need to find a new balancing point. They will fight back and try to revert to what they know. We stay strong, ignore the scale and keep at it. Eventually the body gets the message and catches up to where our minds are.

I didn't look at your food log but think about eating healthy calories and not just counting. I agree with TOM and salt intake. Make sure you're also drinking enough water. You can lose just from that. Don't get discouraged. Looks like you have a lot of people on your side.
Keep at it!