Hello. I would like to help you with your diet, but I need to know your regimen, ration and habits. My email is ***@****
At 5'3" and 154 lbs, you were a bit overweight. 1800/2000 calories/day was probably too many calories for the amount of exercise you were getting. It may not be the number of calories you're currently eating, but possibly the types of food you're eating that's not good for you.
You can transition back to higher calories, simply by adding a couple hundred calories/day, but you may have to increase the amount of exercise you do in order not to gain weight back. It all depends on the types of food you're eating and when you're eating it.
You really need to calculate your own calorie needs, bases on your age, height, weight and activity level...not just pick some arbitrary number that sounds reasonable. We can help you do that, if you like...
It's best to eat larger meals at breakfast and lunch and not so much in the evening. Make sure you're eating plenty of healthful fats, such as avocados, olive and coconut oil, butter, etc to help keep you feeling fuller through the day.