Legitimate Postpartum Weight loss Struggle

This is going to be long, but I’m really hoping someone can give me pointers, or at the very least say “me too”... I feel so terribly desperate.

I am 16 months pp. I gained around 60+lbs (260lbs) during my pregnancy (a good portion water-weight there at the end, & my daughter was 9#), despite regular exercise (CrossFit) 3-5 day/wk up until I was 7 months. And I ate pretty healthy throughout, only giving into cravings moderately (no full pints of ice cream or anything like that).

I got on scale for the first time 2 weeks after delivering (in late September) & I had dropped 32 lbs (228lbs). I was excited for breastfeeding to ‘melt’ my weight off! Well, that didn’t happen...so around the beginning of Nov. I started cutting carbs and just trying to watch what I ate more, & gradually add in light/moderate workouts again. The holidays came and I gave into more indulgences than I should have, & when I hopped on the scale in January I was up to 242 lbs. (?!?!). So I went strict keto and lost 12lbs in about 3 weeks, then nothing. I joined a kickboxing gym and worked out 3-4 days/wk burning 500-900 calories each workout (I wear a HR monitor). Still absolutely nothing except slowly gaining back the 12 I’d lost. For 2+ months. So I stopped the keto diet, but continued working out. Saw very little change over the next couple months -5, +6, repeat. Back at 240lbs. I joined Weight Watchers online & stuck to that pretty well, -5 the first week, so was very excited. Continued, & sloooowly lost around another 5lbs, then gained 3. Repeat for another month. Knowing I had gotten lazy about tracking, I thought that was my problem, so I thought WW meetings would motivate me to track better...lost around 8, the nothing. I wasn’t losing anything else. After 2 months of nothing, I quit WW. Back to the holidays, & as is typical, our eating splurges were more frequent and indulgent than our regular eating. Get on the scale after Jan 1 and I’m sitting right at 240 again. Mind you, I have consistently worked out 4 days/wk all throughout this time, including holidays. So I decide to really buckle down, severely minimize (not eliminate) carbs, amp up veggies, protein, make even more conscious decisions regarding sweets, & I amped up my workout to more HIIT sessions. For 5 weeks now. Got on the scale yesterday...240 lbs!!! I’ve been tracking my food in MFP (the good, the bad and the ugly), & I still only average around 1800-2000/day. My BMR with my activity level is 2864, so just plain mathematically I should be losing weight!!! What the actual efff?!?! What is going on?? I honestly don’t know what I’m doing that’s not working! I am well educated on nutrition and how it works. We eat quite healthy, especially when I hear others talk about their eating habits. We indulge one, maybe two meals on the weekend, but are quite strict during the week. I don’t drink soda, I drink a gallon of water a day... I am falling into a self-loathing depression over my weight and appearance, especially when working so hard.

if you made it this far, bless your heart, & thank you. Would you comment so? Just having someone hear me out means a lot. I’m open to advice. Or, like I said, anyone else dealing with this too??