Nutritional Frustration

I always thought I was a pretty healthy eater, just liked large portions which was what made me carry a few extra pounds. So, i've been following my calorie goal each day religiously - I do not go over and I am as honest as I can possibly be when I enter my foods. My goal was to lose 20lbs - and I am down 10lbs already. I'm 5'2, and currently weigh 115. I want to lose 5-10 more so I can run a personal best in my fall marathon. However, I seemed to have hit a plateau, so I turned my attention to my daily nutritional breakdown. Even though I've been meeting my calorie goals, I am WAYYY over in my sugars and fats...I also notice some vitamin deficits but I take supplements, and I am going to start inputting those, too. I also notice I am sometimes over in my carbs, protein, cholesterol, sodium, etc. Today, I focused on lowering how much sugar I consume. I was going over by 70-100grams, and today I was only over by 5, which I think is pretty good. My fats, sodium and cholesterol were not so good, though. Anyone else struggle with this? How do you find balance? I'm hoping lowering my sugar intake will help me get back to losing weight, but who knows.