Welcome to the forum!
Tldr: Stop exercising, stop tracking calories. Stay under 20 carbs/day, and eat simple keto foods (no processed foods) to satiety until you’re fat adapted and keto feels effortless. Once keto feels effortless, and you’ve got energy to spare, add a single day of exercise back in. Continue to add complexity until your weight loss stalls completely. Reduce complexity until weight loss resumes.
Here is my two cents:
The most important thing in keto is eating to satiety. Exercise and carb-free sweeteners scramble satiety signals for many people. If your satiety signals aren’t working properly, eating to satiety is like following a broken compass. You get nowhere.
In your case, you’re not even eating to satiety so you’re already going in the wrong direction. On top of that you’re eating carb free sweeteners that make the body expect a nice dose of carbs that it never gets. On top of that you’re exercising 4 times per week. Even worse, you’ve switched fuels from carbs to fat, so you’re body is gasping to supply energy from a fuel it barely remembers how to use, and it can’t even recover properly before you attack it with an elliptical again. No wonder you’re worn out and stalled!
Here is what I would do if I were in your shoes:
Stop exercising completely until you are fat adapted and your satiety signals are working properly. You’re demanding way too much of your body and it’s starting to fight back. Stop eating to a calorie target. Eat until you achieve satiety. Once you’re body decides you can be trusted not to starve it to death or wear it into the ground, it’ll settle down and stop fighting you. This is good, because it has 1 billion years of practice managing energy balance, and it has complete control of your endocrine systems including your metabolism. That’s not a fight you want to pick. You’ll probably drop a few more pounds, but in 12-18 months you’ll wake up at 335lbs again wondering wtf happened like the other 99.9% of people who pick a fight with their metabolism and eat to a arbitrary calorie target, lose 100lbs and promptly regain 110lbs. Eat to satiety until you start losing slowly but steadily. Really.
If you don’t enjoy exercise, I don’t think you should be doing it all at this stage of the game. Losing weight while exercising is like skipping algebra and going straight to calculus; some folks can pull it off, but most just end up confused and frustrated. Start with simple and add complexity once you’re able.
If you love exercise so much that you can’t imagine life without it, here is what I would recommend. Once you’ve been on keto for at least another month eating under 20 total (not net) carbs per day, reintroduce whatever exercise you enjoy the most one day per week. Keep eating to satiety. If one day of exercise completely stalls your weight loss, you get to choose between weight loss and exercise. On the other hand if your weight loss continues unabated for a few weeks with one day of exercise, add in another day of exercise that you really enjoy. Continue to do so until you have as much exercise you enjoy, or your weight loss stalls completely. Reduce exercise until weight loss resumes.
If you want to make life really easy, don’t buy any food with more than one ingredient. Don’t eat anything sweet regardless of how many carbs it has. Don’t cook things that are “keto” versions of things that got you into this mess in the first place (keto pizza, keto fudge, etc). Wait until you’re losing weight at a slow and steady pace, and keto feels effortless before you start experimenting with such things.
That’s my two cents. There are 1000 ways to do keto successfully though, and a lot of valid perspectives. Take the specific advice above with a grain of salt, but I think the general advice to start simple and add complexity slowly is reasonably sound. Good luck!