What am I doing wrong?Why am I losing so little weight?

English is not my language so i apologize in advance.

Six years ago I did the keto diet and lost more than 60 kilos, to be honest I wasn't even doing it correctly due to ignorance . I've gone back to old habits and losing 20 kg is turning into a nightmare, I don't know what I'm doing wrong

Details:

Woman

38 years old

155 cm

February weight: 69,100 kg

August weight: 59,400 kg

Activity: Stationary bike 5 days a week between 30 minutes and 1 hour, varying tension and speed

For the first four months, I only consumed a maximum of 800 calories and 20 grams of carbohydrates. I read that restricting calories so much could be the reason for the slow weight loss, So I've been consuming 1200 calories a day for 2 months and I've only lost 300 grams.

I count every calorie, I always check the macronutrients, I never go over 20 grams of carbohydrates

Foods I eat: chicken, beef, pork, eggs, peppers, mushrooms, green beans, eggplant, zucchini, cream, olive oil, butter , cheese

I would appreciate any advice or if someone could point out the mistake I'm unable to see because I'm so frustrated with putting in so much effort for such a mediocre result.