Hi Nettita - it sounds as if you are following a very healthy lifestyle. Congratulations on the weight loss so far.
Some people say that it could help to restart/increase the weight loss if you do interval training. If you don't want to spend more time exercising, maybe just increase the intensity, which should burn a few more calories.
Another option is to stick to the same calories, but eat different foods, in particular, reduce your carbohydrate intake and eat more low-carb (or zero carb) foods. For example minimise your intake of bread, pasta, cereal, rice, potatoes, corn, peas, etc. and eat more low-carb vegetables, lean protein and healthy fats. Some fruit is also high in carbs.
You didn't say how tall you are or how old. If you are short, you could maybe reduce your calorie intake by 100 or 200, but make sure that the calories you eat are high in nutrients. No room for "empty calories" then.
Also, as we age, we need fewer calories of course.
Are you measuring your calories correctly/no chance perhaps of underestimating the number?
For myself, I have to dip below 1200 if I want to lose weight, and even then I lose very slowly (say 1/4 lb a week). It may seem very slow, but any progress is good, and in the long term you will lose the weight, it may just take a couple of months. I believe one can still eat very well and balanced below 1200 if you eat "nutrient bombs", but a lot of people disagree with that - it's just my view and my experience.
E.g. if you eat:
Breakfast: a boiled egg, a small fruit and 3oz yogurt;or an egg-white omelet with veg;
After exercise: 1/2 protein shake;
Lunch: Salad (various ingredients like celery, lettuce, tomatoes, cucumber, radishes, raw cabbage, bean sprouts, capsicum, olives) and 3oz tuna (canned in water);
Snack: 1oz of nuts, raw veg slices or sticks;
Dinner: steamed veg and 4oz grilled chicken (use 1tsp of olive oil during cooking),
you could eat 1000 -1100 calories and cover your nutritional needs, just not your calorie needs (which is the aim),