I admit defeat, I need help!

I (35F, 240lbs) have lost weight before and I have always believed myself well-educated on diet and exercise but I am so lost right now.

I had a very rough couple of years (covid shut down my gym, laid off my dance teacher job, my little sister died tragically, unexplained infertility) and I gained around 40 pounds (150 -> 190 lbs) in four years. Then I got pregnant and managed my weight well. At two weeks postpartum, I was back to my pre-pregnancy weight and looking forward to losing the 40 gained pounds.

Instead, I gained almost 50 pounds (190 -> 240 lbs) in six months. I'm now ten months postpartum so I've spent the last four months trying to lose weight but just being able to maintain and not gain any more.

I'm tracking my calories (my app says around 1800/day to lose 2 pounds/week) and I'm well under that almost everyday. Plus I am still breastfeeding which burns calories (I don't even enter it into my app anymore although I used to).

I've asked for a fitness band for Christmas to track my steps but I am lightly active most days, walking (sometimes up to 5 miles) and doing little workouts at home while wearing my baby in a carrier (so carrying 20 extra pounds).

I'm so disappointed nothing is working so two weeks ago I decided to really step it up. For the last two weeks I've done an extremely limited high protein diet. Eggs/sausage for breakfast. Scoop of protein powder in a glass of milk for lunch. Small protein/veggie dinner (usually salad with chicken). I lost nothing.

Idk if there's any other breastfeeding moms out there but it changes your brain... when I'm hungry it's very hard to ignore (that's admittedly how I got myself into this position, overeating during the first six months of breastfeeding my baby). The last two weeks took a lot of mental fortitude just to step on the scale today and see no change.

So I throw my hands up, I admit defeat, I do not know what I am doing, I do not know how to fix this. I break it into small chunks so my first goal is just 20 pounds. When I started in August I thought that first goal would be easy. But I haven't gotten there and honestly need to lose 100 at this point.

There's more I can explain but thus is already long. Feel free to ask me questions in the comments. TIA for any insight