Have you thought about getting your RMR tested?? I too was using the tools on the internet to figure mine except mine came in at 1150 not the 1400-1500 it should be according to the trainer who tested me. I had mine done at a hospital,laying down,20 min test the whole nine yards for $100. Well worth it for me because at least now I know why nothing was working. She told me to eat around 1400-1500 to lose weight

So reading through the posts you'll notice most do gain weight. The exact same water weight that was initially lost when a diet was started. Same water weight gain that would have happened had you been able to reach goal. Same water weight loss that will occur after you stop a reset and diet again.

But even if you didn't go up to TDEE yet, really proves how depleted you are keeping your glucose stores that you had that much to refill, which stores with water. 500 cal worth is 1 lb total. Required and desired water, it increases your LBM and your metabolism - so a good thing.

In addition to that, for some period of time with a suppressed metabolism from eating so little and doing so much, you will be eating in excess of your TDEE. If you had no loss of measurements or weight - you were eating at maintenance, and now you are eating above maintenance. A very suppressed maintain by your previous choices. At least with exercise, the excess is being put to great use for body improvements, like storing more glucose for those massive cardio workouts you do, which is asking the body to do just that.

So any diet is a stress on the body.
Frequent intense exercise is a stress on the body.
Lack of sleep is, wrong foods can be, other life stresses like worrying over weight.
Guess what is going to fight fat and weight loss - stress.

I'd strongly recommend you mentally accept the fact that for weight loss and hopefully just fat loss - more exercise is NOT better, and in fact will be counter-productive. Too many stresses on the body, and that means removing another stress, like eating enough to cause less of a deficit, which means less weight loss than possibly could be had.

So you are doing so much at the upper aerobic or lower anaerobic end, your request of your body is to store more carbs for those almost total carb burning workouts. More carbs, more water weight.
That means you also will have potential of great weight fluctuations, so to minimize that, you should ONLY weigh on valid days.
Morning after rest day eating normal sodium levels, not sore from last lifting workout.

As to your workout, a way to calm it down.
Those deadman workouts. You even try NOT doing the cardio mix with lifting, and see how much more and harder you can lift? There is a difference between reaching failure because you are lifting a heavy load, and just plain tired. And the response of the body to that load is different too. You are emphasizing cardio with a strength component.
Until you can compare, I'll bet you'd never even realize how much you are impacting having a good lifting routine, with the ability to have fresh muscles really lifting a heavy load.
Maybe that doesn't matter, and that's what you want and you want some improved strength, but not as much as true lifting could provide.
But if you are thinking that is good for weight loss because you are burning a ton of calories, you are not looking at the total picture of calorie burn through the whole day - you are looking at pretty much just the workout.
For instance, a true lifting workout, given proper rest and recovery the next day, will burn more calories for 24-36 hrs after the workout, not just a few hrs.
But you must rest, or at least not add more load to kill the repair your body is attempting to do.

Exercise tears down, rest and recovery and repair is actually what builds back up and stronger. And while in a deficit, that window is even smaller for getting it.

So I'm not sure how in the world you could state you have 3 cardio days and 3 lifting days (really not true lifting though) and call that moderately active for 3-5 hrs weekly.

Your BMR is what your body would like to burn if you could sleep all day.

The whole keep metabolism guessing is a myth by calorie cycling. The fact is your metabolism, if you mean BMR by that, is left with different amount of calories every day anyway. As calories required to just move you mechanically changes, you could eat the exact same amount everyday, and different amounts will be left for your body to apply to BMR functions, repair functions, ect.

I would suggest you calm down the deadman days with NO cardio between the lifts. Let the body recovery, and really lift heavy. You have no idea what you are missing.
Make sure any workout the next day is NOT so intense as to kill the repair process your body would like to do - that is unneeded stress. Keeping HR is Active Recovery HR zone is way to tell usually, which is also badly called the fat-burning zone, but that's it's purpose.
Make sure any workout the day before lifting is not so intense as to make you tired the next day. You probably don't know what you could really lift on fresh muscles.
Again, you probably do indeed lift to failure, because muscles are already tired, not because the load was heavy.

And then with that modified routine, use this to get bodyfat %, best estimate of BMR, better activity calc for your varied activity, and better deficit amount based on amount to lose and your workout type. And macros based on your LBM.
Log your progress in inches lost, and reach goal faster.
Then eating at true maintenance, you'll be able to do more better. Though there is still something to be said for hard days able to be really hard and making great improvement, followed by easy days to actually allow recovery and improving. That doesn't change for the pro's.

http://www.myfitnesspal.com/topics/show/961054-spreadsheet-for-bodyfat-bmr-tdee-progress-tracker

Now, since you are so cardio fit, your RMR is likely to be suppressed anyway, but I wouldn't get tested until you have been eating more, because no needing trying to base your math on suppressed metabolism because of current undereating level.
Wait 3-6 months after eating more if nothing happens.
But with your routine, even modified as I suggested, will likely take your body a while to feel unstressed enough for metabolism to go up well and completely.
So increase calories by about 200 a day for a week or two, then another 200, ect. Go up above your deficit amount, perhaps even to TDEE as suggested here, you'll need it likely with that stress on your body from exercise.

As to the scale being the end-all and be-all. Really? You have to wear your scale weight on your body? Or merely your body needs to look a certain way?

Yikes! Well that might explain it. Your calories are way way way too low. So what ends up happening (I have this issue all the time if my numbers fall) is your body starts hoarding things. So, even though you should be losing weight based on the numbers, you gain because your body is preparing for the long term famine!!!! This will happen even worse if you are eating carbs (I find, anyway, as they store quite readily and your body will attach water like crazy to them).

I would say start a reset pretty quick, and work to get those numbers up for a few weeks. Then, you'll find you can start the deficits and actually see losses.

Good luck! I know how hard it is to bump the numbers when you are seeing gains so low!!! It's my constant struggle!!!!

WATER WEIGHT!!!!!!!!!!!!